epidermal-growth-factor and Body-Weight

Topics: Animal Husbandry; Animals; Biotechnology; Body Weight; Cloning, Molecular; DNA, Recombinant; Epidermal Growth Factor; Growth Hormone; Recombinant Proteins; Somatomedins

The hormonal control of growth in poultry and other species is complex. The available evidence supports the concept that growth hormone and the thyroid hormones are the principal hormones responsible for the attainment of normal growth in the domestic fowl. Other hormones, including somatomedins, epidermal growth hormone, sex steroids, and vitamin D metabolites, are also involved in the control of growth. Considerable study will be required for the elucidation of the exact roles of the various hormones in avian growth.

Topics: Adrenal Cortex Hormones; Animals; Body Weight; Calcitriol; Chickens; Epidermal Growth Factor; Gonadal Steroid Hormones; Growth Hormone; Hormones; Insulin; Nerve Growth Factors; Poultry; Somatomedins; Thyroxine; Triiodothyronine

Topics: Animals; Animals, Newborn; Body Weight; Cells, Cultured; Colostrum; Dogs; Epidermal Growth Factor; Female; Growth Substances; Humans; Infant, Newborn; Insulin; Milk; Milk, Human; Rats

The adaptor protein GAREM has two subtypes. Each is involved in Erk activation signaling downstream of the cell growth factor receptor in cultured cells. Regarding their role in individual animals, we have previously reported that mice deficient in GAREM2, which is highly expressed in the brain, exhibit emotional changes. In this paper, we report an amino acid substitution mutation (K291R) in GAREM1, in a patient with idiopathic short stature, which indicates that the mutant exhibits dominant-negative properties. The GAREM K291R mutant did not promote Erk activation in EGF-stimulated cultured cells. Similar features were also observed in cells in which GAREM1 expression was suppressed by genome editing; along with Erk, phosphorylation of S6 kinase and 4EBP1, whose activation is necessary for cell proliferation and biological growth, were inhibited Furthermore, we generated mice deficient in GAREM1 and showed that the mutant mice are lighter in weight. Overall, the results of this paper suggest that GAREM1 is required for normal growth and for maintaing average body size in humans and mice.

Topics: Adaptor Proteins, Signal Transducing; Animals; Body Weight; Cell Cycle Proteins; Cell Line; Dwarfism; Epidermal Growth Factor; GRB2 Adaptor Protein; Humans; MAP Kinase Signaling System; Mice; Phosphorylation; Ribosomal Protein S6 Kinases

The epidermal growth factor receptor (EGFR) contributes to tumor malignancy via gene amplification and protein overexpression. Previously, we developed an anti-human EGFR (hEGFR) monoclonal antibody, namely EMab-134, which detects hEGFR and dog EGFR (dEGFR) with high sensitivity and specificity. In this study, we produced a defucosylated mouse-dog chimeric anti-EGFR monoclonal antibody, namely E134Bf. In vitro analysis revealed that E134Bf highly exerted antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity against a canine osteosarcoma cell line (D-17) and a canine fibroblastic cell line (A-72), both of which express endogenous dEGFR. Moreover, in vivo administration of E134Bf significantly suppressed the development of D-17 and A-72 compared with the control dog IgG in mouse xenografts. These results indicate that E134Bf exerts antitumor effects against dEGFR-expressing canine cancers and could be valuable as part of an antibody treatment regimen for dogs.

Topics: Animals; Antibodies, Monoclonal; Antibody-Dependent Cell Cytotoxicity; Antineoplastic Agents; Body Weight; CHO Cells; Complement System Proteins; Cricetulus; Dogs; Epidermal Growth Factor; ErbB Receptors; Fucose; Mice; Recombinant Proteins; Tumor Burden; Xenograft Model Antitumor Assays

Improvement in litter traits is the key to profitable pig farming that directly enhances the economic standing of the farmers in developing countries. The present study aimed to explore oestrogen receptor (ESR), epidermal growth factor (EGF), follicle-stimulating hormone beta subunit (FSHβ), prolactin receptor (PRLR) and retinol-binding protein 4 (RBP4) genes as possible candidate genetic markers for litter traits in indigenous pigs of India. The breeds included in the study were Ghungroo, Mali, Niang Megha and Tenyi Vo, and the reproductive traits considered were litter size at birth (LSB), number born alive (NBA), litter weight at birth (LWB), litter size at weaning (LSW) and litter weight at weaning (LWW) at their first parity. PCR-RFLP and primer-based mutation detection methods were used to identify polymorphism, and associations between the genotypes and the traits were analysed using a general linear model. The Ghungroo pigs recorded the best litter performances among the breeds (p < .05, LWB p < .01). Different alleles and genotypes of the genes under study were detected. Short interspersed nuclear element (SINE) -/- genotype of FSHβ revealed significantly higher litter traits (p < .05, LSB p < .01). The LWW was also found to be significantly influenced by ESR BB and AB, EGF AB and BB, and PRLR CC genotypes (p < .05). Although we did not find statistically significant and consistently superior litter traits with respect to different genotypes of other studied genes than genotype SINE -/- of the FSHβ, PRLR CC genotype demonstrated superior performances for all the litter traits. Our study revealed the FSHβ as a potential candidate genetic marker for litter traits in indigenous pig breeds of India.

Topics: Animals; Birth Weight; Body Weight; Breeding; Epidermal Growth Factor; Female; Follicle Stimulating Hormone, beta Subunit; Genotype; Litter Size; Polymorphism, Genetic; Receptors, Estrogen; Receptors, Prolactin; Retinol-Binding Proteins, Plasma; Sus scrofa; Weaning

Silver nanoparticles (AgNPs) can accumulate in various organs after oral exposure. The main objective of the current study is to evaluate the renal toxicity induced by AgNPs after repeated oral exposure and to determine the relevant molecular mechanisms.. In this study, 40 male Wistar rats were treated with solutions containing 30, 125, 300, and 700 mg/kg of AgNPs. After 28 days of exposure, histopathological changes were assessed using hematoxylin-eosin (H&E), Masson's trichrome, and periodic acid-Schiff (PAS) staining. Apoptosis was quantified by TUNEL and immunohistochemistry of caspase-3, and the level of expression of the mRNAs of growth factors was determined using RT-PCR.. Histopathologic examination revealed degenerative changes in the glomeruli, loss of tubular architecture, loss of brush border, and interrupted tubular basal laminae. These changes were more noticeable in groups treated with 30 and 125 mg/kg. The collagen intensity increased in the group treated with 30 mg/kg in both the cortex and the medulla. Apoptosis was much more evident in middle-dose groups (i.e., 125 and 300 mg/kg). The results of RT-PCR indicated that Bcl-2 and Bax mRNAs upregulated in the treated groups (p < 0.05). Moreover, the data related to EGF, TNF-α, and TGF-β1 revealed that AgNPs induced significant changes in gene expression in the groups treated with 30 and 700 mg/kg compared to the control group.. Our observations showed that AgNPs played a critical role in in vivo renal toxicity.

Topics: Animals; Apoptosis; Blood Urea Nitrogen; Body Weight; Caspase 3; Chemical and Drug Induced Liver Injury; Creatinine; Epidermal Growth Factor; Extracellular Matrix Proteins; Gene Expression; Immunohistochemistry; In Situ Nick-End Labeling; Kidney; Male; Metal Nanoparticles; Organ Size; Rats, Wistar; RNA, Messenger; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

We investigated efficacy of in ovo application of epidermal growth factor (EGF) on intestinal expression of EGF receptor (EGFR) during embryogenesis (experiment 1) and posthatch growth performance and gastrointestinal development in broiler chickens (experiment 2). In experiment 1, 450 fertile Ross 708 eggs were allocated to 3 groups (150 eggs/group): 1) control, 2) 160 μg EGF/kg of egg, and 3) 640 μg of EGF/kg of egg. Eggs were candled for live embryos on day 16 and injected with the respective treatment solutions on day 17 and sampled for jejunal tissue from day 17 to hatch for EGFR analyses. There was no effect of EGF (P > 0.05) on EGFR expression on day 17 to 20; however, on day 21, EGF increased (P < 0.05) EGFR expression in EGF birds relative to control birds. In experiment 2, 600 fertile Ross 708 eggs were allocated to 5 treatments: 1) intact, no puncture or injection, 2) punched but not injected, 3) control, no EGF, 4) 80 μg of EGF/kg of egg, and 5) 160 μg of EGF/kg of egg. The eggs were incubated and candled for live embryos on D 19, treated, and subsequently transferred to the hatcher. Upon hatching, chicks were weighed, and 90 chicks per treatment placed in cages (15 birds/cage) and allowed free access to a standard antibiotic-free corn-soybean diet for 21 D. Feed intake and body weight were monitored on a weekly basis. Samples of birds were necropsied on D 0, 7, 14, and 21 for measurements of intestinal weight and jejunal histomorphology and excreta samples taken on D 3 to 5 and 17 to 19 for apparent retention of dry matter. There was no EGF effect (P > 0.05) on any posthatch response criteria. In conclusion, in ovo application of EGF increased EGFR expression but had no effect on posthatch growth performance, DM retention, and intestinal development. The lack of EGF effect on posthatch response was surprising but suggested in ovo application of EGF may not be a viable approach.

Topics: Animals; Body Weight; Chick Embryo; Chickens; Epidermal Growth Factor; ErbB Receptors; Gene Expression Regulation; Intestines; Zygote

To assess changes in metabolic risk factors and cancer-related growth factors associated with short-term abstinence from alcohol.. Prospective, observational study.. Single tertiary centre.. Healthy subjects were recruited based on intention to: (1) abstain from alcohol for 1 month (abstinence group), or (2) continue to drink alcohol (control group). Inclusion criteria were baseline alcohol consumption >64 g/week (men) or >48 g/week (women). Exclusion criteria were known liver disease or alcohol dependence.. The primary outcome was change in insulin resistance (homeostatic model assessment (HOMA) score). Secondary outcomes were changes in weight, blood pressure (BP), vascular endothelial growth factor (VEGF), epidermal growth factor (EGF) and liver function tests. Primary and secondary outcomes were adjusted for changes in diet, exercise and cigarette smoking.. The abstinence group comprised 94 participants (mean age 45.5 years, SD ±1.2) and the control group 47 participants (mean age 48.7 years, SD ±1.8). Baseline alcohol consumption in the abstinence group was 258.2 g/week, SD ±9.4, and in the control group 233.8 g, SD ±19.0. Significant reductions from baseline in the abstinence group (all p<0.001) were found in: HOMA score (-25.9%, IQR -48.6% to +0.3%), systolic BP (-6.6%, IQR -11.8% to 0.0%), diastolic BP (-6.3%, IQR -14.1% to +1.3%), weight (-1.5%, IQR -2.9% to -0.4%), VEGF (-41.8%, IQR -64.9% to -17.9%) and EGF (-73.9%, IQR -86.1% to -36.4%). None of these changes were associated with changes in diet, exercise or cigarette smoking. No significant changes from baseline in primary or secondary outcomes were noted in the control group.. These findings demonstrate that abstinence from alcohol in moderate-heavy drinkers improves insulin resistance, weight, BP and cancer-related growth factors. These data support an independent association of alcohol consumption with cancer risk, and suggest an increased risk of metabolic diseases such as type 2 diabetes and fatty liver disease.

Topics: Adult; Alcohol Drinking; Alcoholism; Blood Pressure; Body Weight; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Epidermal Growth Factor; Ethanol; Fatty Liver; Female; Humans; Insulin Resistance; Liver; Liver Function Tests; Male; Middle Aged; Neoplasms; Prospective Studies; Risk Factors; Vascular Endothelial Growth Factor A

Gene expression of epidermal growth factor (EGF), transforming growth factor-α (TGF-α) and EGF receptor (EGF-R) and the localization of the corresponding proteins in the canine testis were studied. Levels of mRNA expressions were determined by semiquantitative reverse transcription polymerase chain reaction in the testes of the peripubertal (4-6 months), young adult (3-4 years), advanced adult (7-8 years) and senescent (11-16 years) groups. The EGF-R mRNA level in the testes of the peripubertal group was significantly higher than those in the other groups, whereas there was no difference in EGF and TGF-α mRNA levels among groups. Immunohistochemical stainings for EGF, TGF-α and EGF-R in the testis revealed that immunoreactivity in the seminiferous epithelium and Sertoli cell was weak and nonspecific for the stage of spermatogenesis, and distinct staining was found in Leydig cells. These results suggest that the EGF family of growth factors may be involved in testicular maturation and function in the dog.

Topics: Animals; Body Weight; Dogs; Epidermal Growth Factor; ErbB Receptors; Gene Expression Regulation; Immunohistochemistry; Leydig Cells; Male; RNA, Messenger; Seminiferous Epithelium; Sertoli Cells; Testis; Transforming Growth Factor alpha

A growing number of studies suggest that epidermal growth factor (EGF) plays an important role in early-weaned animals. The objective of this experiment was to compare the biological activity of intracellularly expressed EGF (IE-EGF), extracellularly expressed EGF (EE-EGF), and tagged EGF (T-EGF) from Saccharomyces cerevisiae (S. cerevisiae) both in vivo and in vitro. Strains of S. cerevisiae expressing IE-EGF, EE-EGF, and T-EGF were designated INVSc1-IE(+), INVSc1-EE(+), and INVSc1-TE(-), respectively. The production performance, intestinal development, physio-biochemical indexes, and immunological function of early-weaned rats were measured in vivo to evaluate the biological activity of IE-EGF, EE-EGF, and T-EGF. In addition, the proliferation of rat enterocyte was also measured in vitro. In the in vivo experiment, the recombinant S. cerevisiae was shown to survive throughout the intestinal tract. The production performance (e.g., body weight) and intestinal development (e.g., mean villous height, crypt depth, total protein, DNA, and RNA) of the rats were significantly enhanced in the INVSc1-IE(+) group compared with the INVSc1-EE(+) and INVSc1-TE(-) groups (P < 0.05). However, the levels of lactate dehydrogenase (LDH), immunoglobulin A (IgA), immunoglobulin M (IgM), and immunoglobulin G (IgG) showed no difference in the INVSc1-IE(+) group compared to the INVSc1-EE(+) and INVSc1-TE(-) groups (P > 0.05), with the only significant difference being found for creatine kinase (CK) (P < 0.05). In the in vitro experiment, the proliferation of enterocyte was significantly stimulated by both IE-EGF and EE-EGF compared with T-EGF (P < 0.05). Herein, IE-EGF is more suitable for application to early-weaned animals compared with EE-EGF and T-EGF.

Topics: Animals; Body Weight; Cell Proliferation; Cells, Cultured; Enterocytes; Epidermal Growth Factor; Intestines; Microbial Viability; Molecular Sequence Data; Rats; Recombinant Proteins; Saccharomyces cerevisiae; Sequence Analysis, DNA

Obese infants are more susceptible to develop adulthood obesity and its related comorbidities. Previous studies have shown the presence of hormones and growth factors in maternal breast milk that may influence infant adiposity. The aim of this study was to investigate differences in concentrations of three hormones and two growth factors in the breast milk of mothers with obese and non-obese infants.. In this cross-sectional study, 40 mothers with overweight or obese infants (weight for length percentile >97) and 40 age-matched mothers with normal-weight infant (-10 < weight for length percentile < 85) who were between 2 and 5 months of age were enrolled. Anthropometric indices of infants and mothers were measured by routine methods. Breast milk concentrations of ghrelin and adiponectin, leptin, epithelial growth factor (EGF) and insulin-like growth factor-1 (IGF-1) were measured using enzyme-linked immunosorbent assay methods.. The mean breast milk concentration of ghrelin was higher in mothers with normal-weight infants, 137.50 pg/ml, than in mothers with obese infants, 132.00 pg/ml (P=0.001). This was also true regarding the concentration of EGF in mothers with (0/04 ng/ml) and without (0/038 ng/ml) normal-weight infants (P=0.01). No significant differences were observed in concentrations of leptin, adiponectin and IGF-1 between two groups (P > 0.05). There was also a significant positive correlation between EGF and ghrelin in both groups.. This study revealed that there was a correlation between ghrelin and EGF level in breast milk of mothers with obese and non-obese infants, suggesting a possible regulatory effect of these two hormones on weight in infants.

Topics: Adiponectin; Adult; Body Weight; Breast Feeding; Case-Control Studies; Child Development; Cross-Sectional Studies; Epidermal Growth Factor; Female; Ghrelin; Humans; Infant; Infant Nutritional Physiological Phenomena; Insulin-Like Growth Factor I; Leptin; Milk, Human; Mothers; Obesity; Overweight; Pregnancy; Young Adult

Topics: Animals; Animals, Newborn; Body Weight; Epidermal Growth Factor; Skin; Skin Temperature

The aim of this study is to investigate the anti-cancer effect of the bispecific diphtheria toxin (DT) based immunotoxin DTATEGF, which targets both the epidermal growth factor (EGF) receptor (EGFR) and the urokinase-type plasminogen activator (uPA) receptor (uPAR) in vitro and in vivo when delivered by convection-enhanced delivery (CED) via an osmotic minipump in a human metastatic non-small cell lung cancer (NSCLC) brain tumor mouse xenograft model. The effects of the bispecific immunotoxin DTATEGF, and monospecific DTAT, DTEGF and control DT at various concentrations were tested for their ability to inhibit the proliferation of human metastatic NSCLC PC9-BrM3 cells in vitro by MTT assay. A xenograft model of human metastatic NSCLC intracranial model was established in nude mice using the human NSCLC PC9-BrM3 cell line genetically marked with a firefly luciferase reporter gene. One microgram of DTATEGF in the treatment group or control DT in the control group was delivered intracranially by CED via an osmotic minipump. The bioluminescent imaging (BLI) was performed at day 7, 14, 1 month, 2 months, and 3 months. Kaplan-Meier survival curves for the two groups were generated. The brain tissue samples were stained by hematoxylin and eosin for histopathological assessment. In vitro, DTATEGF could selectively kill PC9-BrM3 cells and showed an IC(50) less than 0.001 nM, representing a more than 100- to 1000-fold increase in activity as compared to monospecific DTAT and DTEGF. In vivo, mice with tumors were treated intracranially with drug via CED where the results showed the treatment was successful in providing a survival benefit with the median survival of mice treated with DTATEGF being significantly prolonged relative to controls (87 vs. 63 days, P = 0.006). The results of these experiments indicate that DTATEGF kills the NSCLC PC9-BrM3 cell line in vitro, and when it is delivered via CED intracranially, it is highly efficacious against metastatic NSCLC brain tumors. DTATEGF is a safe and effective drug where further preclinical and clinical development is warranted for the management of metastatic brain tumors.

Topics: Animals; Antineoplastic Agents; Body Weight; Brain Neoplasms; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Cell Proliferation; Diphtheria Toxin; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Delivery Systems; Epidermal Growth Factor; Humans; Kaplan-Meier Estimate; Mice; Mice, Nude; Neoplasm Transplantation; Recombinant Fusion Proteins; Time Factors; Xenograft Model Antitumor Assays

The effectiveness of near-infrared imaging (NIR) interrogation of epidermal growth factor receptor (EGFR) expression as a sensitive biomarker of oral squamous cell carcinoma (OSCC) response to arsenic trioxide therapy was studied in mice.. A431 OSCC in vitro were exposed to 0 µM, 0.5 µM, 2.5 µM, or 5 µM of As(2)O(3) for 0 h, 24 h, 48 h and 72 h. Confocal microscopy and flow cytometry confirmed EGFR expression and demonstrated a sensitivity dose-related signal decline with As(2)O(3) treatment. Next, mice with pharynx-implanted A431 cells received As(2)O(3) i.p. every 48 h at 0.0, 0.5, 2.5, or 5 mg/kg/day (n = 6/group) from day 0 to 10. An intravenous NIR probe, EGF-Cy5.5, was injected at baseline and on days 4, 8, and 12 for dynamic NIR imaging. Tumor volume and body weights were measured three times weekly.. In vitro, A431 EGFR expression was well appreciated in the controls and decreased (p<0.05) with increasing As(2)O(3) dose and treatment duration. In vivo EGFR NIR tumor signal intensity decreased (p<0.05) in As(2)O(3) treated groups versus controls from days 4 to 12, consistent with increasing dosage. Tumor volume diminished in a dose-related manner while body weight was unaffected. Immunohistochemical staining of excised tumors confirmed that EGFR expression was reduced by As(2)O(3) treatment in a dose responsive pattern.. This study demonstrates for the first time that OSCC can be interrogated in vivo by NIR molecular imaging of the EGFR and that this biomarker is effective for the longitudinal assessment of OSCC response to As(2)O(3) treatment.

Topics: Animals; Antineoplastic Agents; Arsenic Trioxide; Arsenicals; Biomarkers, Tumor; Body Weight; Carbocyanines; Carcinoma, Squamous Cell; Dose-Response Relationship, Drug; Epidermal Growth Factor; ErbB Receptors; Gene Expression; Injections, Intraperitoneal; Injections, Intravenous; Magnetic Resonance Imaging; Mice; Mice, Nude; Mouth Neoplasms; Neoplasms, Experimental; Oxides; Recombinant Fusion Proteins; Spectroscopy, Near-Infrared; Tumor Burden; Tumor Cells, Cultured

Evidence from animal studies indicates the importance of an interaction between the sympathetic nervous system and the endothelium for cardiovascular regulation. However the interaction between these two systems remains largely unexplored in humans. The aim of this study was to investigate whether directly recorded sympathetic vasoconstrictor outflow is related to a surrogate marker of endothelial function in healthy individuals.. In 10 healthy normotensive subjects (3 f/7 m), (age 37+/-11 yrs), (BMI 24+/-3 kg/m(2)) direct recordings of sympathetic action potentials to the muscle vascular bed (MSNA) were performed and endothelial function estimated with the Reactive Hyperaemia- Peripheral Arterial Tonometry (RH-PAT) technique. Blood samples were taken and time spent on leisure-time physical activities was estimated. In all subjects the rate between resting flow and the maximum flow, the Reactive Hyperemic index (RH-PAT index), was within the normal range (1.9-3.3) and MSNA was as expected for age and gender (13-44 burst/minute). RH-PAT index was inversely related to MSNA (r = -0.8, p = 0.005). RH-PAT index and MSNA were reciprocally related to time (h/week) spent on physical activity (p = 0.005 and p = 0.006 respectively) and platelet concentration (PLT) (p = 0.02 and p = 0.004 respectively).. Our results show that sympathetic nerve activity is related to a surrogate marker of endothelial function in healthy normotensive individuals, indicating that sympathetic outflow may be modulated by changes in endothelial function. In this study time spent on physical activity is identified as a predictor of sympathetic nerve activity and endothelial function in a group of healthy individuals. The results are of importance in understanding mechanisms underlying sympathetic activation in conditions associated with endothelial dysfunction and emphasise the importance of a daily exercise routine for maintenance of cardiovascular health.

Topics: Activities of Daily Living; Adult; Apolipoproteins; Biomarkers; Blood Pressure; Body Mass Index; Body Weight; Cholesterol; Endothelium, Vascular; Epidermal Growth Factor; Exercise; Female; Humans; Insulin-Like Growth Factor I; Linear Models; Male; Middle Aged; Multivariate Analysis; Muscle, Skeletal; Sympathetic Nervous System; Triglycerides; Young Adult

Recombinant human epidermal growth factor (rhEGF) has potential benefit for the mucositis induced by radiation therapy as a therapeutic setting. In this study, we aimed to investigate the effects of rhEGF treatment on the radiation-induced changes in epithelial transport function, before the occurrence of the definitive histological mucosal changes. C3H/He mice received 0, 4, or 8 Gy irradiation and/or EGF treatment (rhEGF 0, 1 and 5mg/kg, i.p., 5 days). At day 7, we recorded short circuit current (I(sc)) of the upper tracheal epithelium using the flow-type Ussing chamber method, with histological analysis. As a result, there was no evident pathological change in the epithelium from the irradiated and/or rhEGF treated mice at day 7. The initial level of I(sc) and amiloride-sensitive I(sc) (ΔI(sc,Amil)) were decreased after 8 Gy irradiation, reflecting suppression of basal Na+ absorption. The decreased ΔI(sc,Amil) was recovered by rhEGF treatment. In conclusion, epithelial Na+ channel-dependent basal Na+ absorption was primarily affected by irradiation, before the pathological changes. The recovery of basal Na+ absorption (ΔI(sc,Amil)) suggested a potentially beneficial effect of early rhEGF treatment for irradiation-induced suppression of the upper aerodigestive epithelial functions.

Topics: Absorption; Animals; Body Weight; Epidermal Growth Factor; Epithelium; Female; Humans; Ion Transport; Mice; Mice, Inbred C3H; Mucositis; Radiation Injuries, Experimental; Radiation-Protective Agents; Recombinant Proteins; Sodium; Trachea

We generated transgenic mice to study the in vivo role of the cytoplasmic domain of human proEGF (proEGFcyt). Post-pubertal proEGFcyt transgenic (tg) mice displayed an up to 15% reduction in body weight, including smaller kidney and brain weights as compared to control littermates. Renal histology, gene expression profiles, and functional parameters were normal. In both sexes, serum levels of IGFBP-3 were reduced. Circulating IGF-I/IGF-II levels were unchanged. Histomorphological analysis revealed isolated foci of liver necrosis specific to proEGFcyt tg mice. In conclusion, we identified proEGF cytoplasmic domain as a novel modulator of whole body and organ-specific growth in mice.

Topics: Animals; Body Weight; Cytoplasm; Epidermal Growth Factor; Female; Gene Expression Profiling; Immunohistochemistry; Insulin-Like Growth Factor Binding Protein 3; Male; Mice; Mice, Transgenic; Organ Size; Protein Precursors

We have previously demonstrated in rats that Chagas' disease affects the salivary glands, by promoting an enlargement of the submandibular gland. In order to further investigate possible functional alterations on infected submandibular glands, the objective of the present study was to analyze epidermal growth factor (EGF) expression on rat submandibular glands during Trypanosoma cruzi infection. Results demonstrated that infected rats presented lower levels of testosterone, and morphological changes in the granular convoluted tubule (GCT) cells of the submandibular glands, along with acinar enlargement and delayed ductal maturation at the developing granular ducts. Immunohistochemistry analysis additionally showed that only few cells immunolabelled with anti-EGF on infected rats during the acute phase of Chagas' disease, while after 64 and 90 days (chronic phase) of infection, EGF expression was similar to non-infected rats. The present findings suggest that at the acute phase of Chagas' disease, lower levels of testosterone may lead to a delayed maturation of GCT, which positively correlates with decreased EGF production by submandibular glands cells.

Topics: Animals; Body Weight; Chagas Disease; Epidermal Growth Factor; Immunohistochemistry; Male; Rats; Submandibular Gland; Testosterone; Trypanosoma cruzi

Sprouty genes encode cytoplasmic membrane-associated proteins that inhibit receptor tyrosine kinase signaling. Four orthologs of Drosophila Sprouty (dSpry) (Sprouty1-4) have been identified in mammals. Physiological function of Sprouty1 and Sprouty2 has been investigated using gene targeting approaches, however to date detailed examination of Sprouty4 knockout (KO) mice has not been reported. In this study, Sprouty4 KO mice were generated and characterized. Although a significant fraction of Sprouty4 KO mice died shortly after birth due to mandible defects, the remainder were viable and fertile. Growth retardation was observed for most Sprouty4-deficient mice, with nearly all Sprouty4 KO mice having polysyndactyly. ERK activation was sustained in Sprouty4 KO mouse embryonic fibroblasts (MEFs) in response to FGF, but not to EGF. Sprouty2 and Sprouty4 double KO (DKO) mice were embryonic lethal and showed severe defects in craniofacial, limb, and lung morphogenesis. These findings suggest both redundant and non-redundant functions for Sprouty2 and Sprouty4 on embryonic development and FGF signaling.

Topics: Adaptor Proteins, Signal Transducing; Animals; Body Weight; Cells, Cultured; Embryo, Mammalian; Epidermal Growth Factor; Fibroblast Growth Factors; Gene Expression Regulation, Developmental; Genes, Lethal; Intracellular Signaling Peptides and Proteins; Lung; Membrane Proteins; Mice; Mice, Knockout; Nerve Tissue Proteins; Phenotype; Protein Serine-Threonine Kinases; Signal Transduction; Tissue Culture Techniques

Transforming growth factor-alpha (TGF-alpha) is abnormally expressed in autosomal recessive polycystic kidney disease (ARPKD). Tumor necrosis factor-alpha converting enzyme (TACE), a metalloproteinase, mediates TGF-alpha processing. In this study, we sought to determine whether TGF-alpha was an absolute requirement for renal cystogenesis and whether its absence would modulate disease severity or related growth factors/receptors expression. Bpk heterozygotes were bred with TGF-alpha null mice to produce cystic and noncystic offspring with or without TGF-alpha. Assessments included kidney weight (KW), body weight (BW), blood urea nitrogen (BUN), and kidney and liver immunohistology. Western analysis assessed kidney expression of amphiregulin (AR), epidermal growth factor (EGF), heparin-binding EGF (HB-EGF), and their receptors, EGFR and ErbB4. A PCR-based methodology for genotyping bpk mice was also developed. No significant differences in KW, BW, KW/BW%, or BUN were seen in cystic mice with versus without TGF-alpha. Cystic kidney disease and liver disease histology were similar. AR, EGF, HB-EGF, EGFR, and ErbB4 were abnormally expressed to an equal degree in kidneys of mice with versus without TGF-alpha. Although previous data suggest a critical role of TGF-alpha in murine PKD, these data show that TGF-alpha is not required for renal cyst formation or kidney or liver disease progression. We speculate that the therapeutic effect of WTACE2 could have been due to effects on several TACE targets, including TGF-alpha, AR, and ErbB4, as well as metalloproteinases other than TACE.

Topics: ADAM Proteins; ADAM17 Protein; Alleles; Amphiregulin; Animals; Blood Urea Nitrogen; Body Weight; Disease Progression; EGF Family of Proteins; Epidermal Growth Factor; ErbB Receptors; Genes, Recessive; Genotype; Glycoproteins; Heparin-binding EGF-like Growth Factor; Intercellular Signaling Peptides and Proteins; Kidney; Kidney Diseases, Cystic; Liver; Metalloendopeptidases; Mice; Mice, Inbred C57BL; Mutation; Organ Size; Phenotype; Polycystic Kidney Diseases; Polymerase Chain Reaction; Receptor, ErbB-4; Transforming Growth Factor alpha

In the adult pancreas, pre-existing beta cells, stem cells, and endocrine progenitor cells residing in the duct lining are considered important sources for beta-cell regeneration. A member of the epidermal growth factor (EGF) family, heparin binding (HB)-EGF, may promote this process. We examined whether HB-EGF gene transduction into duct cells could promote beta-cell regeneration.. We administered an HB-EGF adenovirus vector construct to male Institute of Cancer Research mice by retrograde injection through the pancreatic duct. We also performed HB-EGF gene transduction into cultured duct cells.. On immunohistochemical and histomorphometric analysis of the experimental group, insulin-positive cells differentiated from duct cells, and the 5-bromo-2-deoxyuridine labeling index of beta cells was significantly increased. beta-cell mass was also increased, and the glucose tolerance of diabetic mice was improved at 12 weeks after injection. Using cultured pancreatic duct cells, we confirmed that HB-EGF gene transduction induced both insulin gene expression and insulin production by these cells.. These results indicate that HB-EGF gene transduction into adult pancreatic duct cells not only promotes the proliferation of pre-existing beta cells but also leads to beta-cell differentiation from duct cells, and the resulting increase in beta-cell mass improves glucose tolerance.

Topics: Adenoviridae; Animals; Body Weight; Bromodeoxyuridine; Cells, Cultured; Diabetes Mellitus, Experimental; Epidermal Growth Factor; Genetic Therapy; Glucose Tolerance Test; Heparin-binding EGF-like Growth Factor; Homeodomain Proteins; Immunohistochemistry; Injections; Intercellular Signaling Peptides and Proteins; Islets of Langerhans; Male; Mice; Mice, Inbred ICR; Pancreatic Ducts; Regeneration; Reverse Transcriptase Polymerase Chain Reaction; Trans-Activators

Human colon cancer cells were injected subcutaneous in nude mice. After 8 days the animals were divided in two groups, the first group received triple therapy with octreotide, galanin and serotonin (40 microg/kg body weight/day) through an ALZET osmotic pump implanted intraperitoneally (i.p.) for 14 days, followed by 5 days of subcutaneous injections (200 microg/kg body weight/ day). The second group was injected i.p. for 5 days with 5-fluorouracil/leukovorin (5-FU/LV) at concentrations of 4 mg and 2 mg/kg body weight, respectively. After 9 days without any treatment, the mice received i.p. injection with 5-FU/LV (20 mg and 10 mg/kg body weight/day, respectively) for another 5 days. The volume and weight of the tumours were measured at the end of the experiment. Apoptosis, proliferation, blood vessels, epidermal growth factor (EGF) and vascular endothelial cell growth factor (VEGF) were detected with immunocytochemistry. Apoptosis was also detected using the TUNEL-method. Quantification was performed using computed image analysis. There was no statistical significance between tumours treated with 5-FU/LV or triple therapy regarding the volume and weights of the tumours, apoptotic, proliferation, VEGF indces and the density of tumour blood vessels. The EGF labelling index was, however significantly lower in the tumours treated with triple therapy than those treated with 5-FU/LV. In conclusion, treatment with triple therapy using octreotide, galanin and serotonin appear to be comparable with 5-FU/LV that is the standard chemotherapeutic agent for colorectal cancer.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Body Weight; Cell Line, Tumor; Cell Proliferation; Colonic Neoplasms; Epidermal Growth Factor; Fluorouracil; Galanin; Humans; Immunohistochemistry; In Situ Nick-End Labeling; Leucovorin; Mice; Mice, Nude; Neovascularization, Pathologic; Octreotide; Platelet Endothelial Cell Adhesion Molecule-1; Poly(ADP-ribose) Polymerases; Serotonin; Vascular Endothelial Growth Factor A; Xenograft Model Antitumor Assays

An in vivo approach was taken to assess the biological significance of heparin-binding EGF-like growth factor (HB-EGF) using transgenic mice. Transgenic mice were generated using the pIRES-EGFP vector expressing a bicistronic mRNA containing both human HB-EGF (hHB-EGF) and enhanced green fluorescent protein (EGFP) coding sequences under the regulation of the cytomegalovirus immediate-early (CMV-IE) promoter. As a marker for transgene expression, EGFP fluorescence in 5 microm tissue sections was evaluated. To confirm HB-EGF expression in EGFP-containing tissues, HB-EGF mRNA was analyzed by RT-PCR and Northern blot analysis. Protein levels of HB-EGF and insulin-like growth factor binding protein-3 (IGFBP-3), a molecule that stabilizes IGFs, which in turn helps to promote growth, were analyzed by Western blot. Also, the weights of transgenic mice were compared with the weights of wild type non-transgenic littermates over a 10-week period. EGFP fluorescence, RT-PCR and Northern analysis of a variety of tissues from hHB-EGF transgenic mice indicate recombinant EGFP/hHB-EGF mRNA expression in kidney, liver, lung and stomach. Western blot analysis confirmed that HB-EGF protein levels were greater in these tissues from hHB-EGF transgenic mice compared to wild type non-transgenic littermates. IGFBP-3 protein was absent in serum of transgenic mice prior to the onset of puberty, but indistinguishable from wild type non-transgenic mice after puberty. Furthermore, IGFBP-3 and IGFBP-4 mRNA were downregulated in the kidney, but not liver or lung of the transgenic mice. In accordance with reduced IGFBP-3 and -4 levels, hHB-EGF transgenic mice exhibited a 20% decrease in weight prior to 6 weeks of age compared to wild type non-transgenic littermates. Our laboratory has generated a biologically functional transgenic mouse model exhibiting increased expression of hHB-EGF in kidney, liver, lung and stomach. Overexpression of hHB-EGF affected the growth rate of these transgenic mice possibly through a pathway involving IGFBP-3 and IGFBP-4.

Topics: Animals; Blotting, Western; Body Weight; Cells, Cultured; Down-Regulation; Epidermal Growth Factor; Female; Fibroblasts; Gene Expression Regulation, Developmental; Green Fluorescent Proteins; Heparin-binding EGF-like Growth Factor; Humans; Insulin-Like Growth Factor Binding Protein 3; Insulin-Like Growth Factor Binding Protein 4; Intercellular Signaling Peptides and Proteins; Male; Mice; Mice, Transgenic; Recombinant Proteins; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Tissue Distribution

Human colon cancer cells were injected sub-cutaneously into 30 nude mice. After 8 days, the animals were divided into 3 equal groups. The first and second groups received an i.p. injection with 5-fluorouracil/leukovorin (5-FU/LV) for 5 days (20 mg and 10 mg/kg body weight respectively). On the first day of 5-FU/LV treatment, the first group received an i.p. injection of irinotecan (2.5 mg/kg body weight), and the second group received an i.p. injection with oxaliplatin (1 mg/kg body weight). The third group were injected i.p. with 100 microl saline solution containing octreotide, galanin and serotonin. Injections were given 3 times daily for 5 days with a total dose of 150 microg/kg body weight/day. Three days after the treatment, the animals were sacrificed. Whereas the animals treated with triple therapy held a stable body weight, animals treated with 5-FU/LV-irinotecan and 5-FU/LV-oxaliplatin had gradual weight loss, which amounted to approximately 25% of their body weight at the end of the experiment. Moreover, 2 mice in the group treated with 5-FU/LV-irinotecan died, most probably due to side effects. There was no statistically significant difference between the 3 groups regarding tumour proliferation, apoptosis, blood vessel density, EGF- and VEGF-expression. Treatment with triple therapy using octreotide, galanin and serotonin appear to be comparable to 5-FU/LV in combination with irinotecan and oxaliplatin. However, triple therapy seems to have a better safety profile.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Body Weight; Camptothecin; Cell Proliferation; Colonic Neoplasms; Epidermal Growth Factor; Female; Fluorouracil; Galanin; Immunohistochemistry; In Situ Nick-End Labeling; Irinotecan; Leucovorin; Mice; Mice, Inbred BALB C; Mice, Nude; Neovascularization, Pathologic; Octreotide; Organoplatinum Compounds; Oxaliplatin; Platelet Endothelial Cell Adhesion Molecule-1; Poly(ADP-ribose) Polymerases; Serotonin; Time Factors; Treatment Outcome; Vascular Endothelial Growth Factor A; Xenograft Model Antitumor Assays

Several studies have confirmed a decrease in the quality and quantity of milk of mothers with diabetes during lactation. However, it remains unclear how maternal diabetes affects the offspring specifically during lactation. The aim of this study was to evaluate body and mandibular growth and tooth eruption in pups suckling from diabetic dams. The study was performed on 13 Wistar rat pups that were born to dams that were subjected to experimental diabetes on the day of parturition. Body weight and body size were recorded regularly throughout the study. The experimental pups and a group of eight age-matched pups suckling from nondiabetic dams were killed at weaning. Both hemimandibles were excised and fixed. Right hemimandibles were radiographed to assess mandibular growth and tooth eruption. The left hemimandibles were processed to obtain buccolingually oriented sections at the level of the first mesial root of the first lower molar. Histologic and histomorphometric studies were performed. Results showed that body weight and body size were significantly lower in experimental animals at weaning compared with their age-matched controls. Smaller mandible size and reduced tooth eruption in experimental animals compared with controls were observed. The length, width, and bone volume of the developing alveolus were reduced in experimental animals compared with controls. The results obtained in this study allow the conclusion that suckling from diabetic dams results in reduced body, mandible size, and tooth eruption of the pups at weaning.

Topics: Animals; Animals, Suckling; Body Weight; Diabetes Mellitus, Experimental; Epidermal Growth Factor; Female; Mandible; Rats; Rats, Wistar; Time Factors; Tooth; Tooth Eruption

In rodents, submandibular salivary glands accumulate a number of biologically active peptides, and release some of them to both saliva and the bloodstream. Surgical removal of these glands (sialoadenectomy) alters the ability of the liver to regenerate after partial hepatectomy. We show here that 5 weeks after surgery, the liver of sialoadenectomized mice contained 40% fewer hepatocytes than the liver of sham-operated mice. We did not obtain evidence of necrotic cell death after surgery. In contrast, sialoadenectomy transiently increased apoptotic hepatocyte death, as revealed by terminal deoxynucleotidyl transferase(TdT)-mediated dUTP nick-end labeling (TUNEL) assay. DNA synthesis was determined in vivo by the incorporation of bromo-deoxyuridine (BrdU) into hepatocyte nuclei. BrdU-labeling progressively increased after sialoadenectomy. We conclude that sialoadenectomy induced a transient wave of apoptotic cell death followed by a rise in DNA synthesis but not by cell division. This reduced cell number but increased mean cell volume. In spite of these alterations in cellularity, the liver responded adequately to several stressful conditions, as judged by the lack of any differential effect of sialoadenectomy on liver glycogen and plasma glucose concentration after immobilization, aggressive encounter, or fasting. However, the liver of sialoadenectomized mice was more sensitive to the effect of a non-lethal dose of bacterial lipopolysaccharide (LPS) combined with d-galactosamine, as shown by the enhanced rise in plasma alanine aminotransferase and aspartate aminotransferase, and liver myeloperoxidase (MPO) activities. All these results indicate that a submandibular salivary glands-liver axis is involved in the maintenance of liver structure in mice. A disturbance of this axis induces an adaptive response that preserves the metabolic function of the liver but renders it more sensitive to bacterial endotoxins.

Topics: Animals; Apoptosis; Body Weight; Cells, Cultured; Epidermal Growth Factor; Hepatectomy; Hepatocytes; In Situ Nick-End Labeling; Liver; Mice; Organ Size; Submandibular Gland

Increasing beta-cell mass and/or function could restore glucose homeostasis in diabetes mellitus. Hitherto, trophic factors for beta-cell regeneration after toxic events have been difficult to identify. We evaluated the application of gastrin and epidermal growth factor after alloxan-induced pancreatic beta-cell damage.. After alloxan treatment (70 mg/kg), mice were implanted with Alzet osmotic minipumps releasing gastrin and epidermal growth factor for one week. We monitored glycaemia, did histological analyses of the pancreata and quantified pancreatic beta-cell mass and insulin content.. Alloxan treatment alone resulted in a persisting hyperglycaemic state. Combined gastrin and epidermal growth factor treatment restored normoglycaemia in 3 days, an effect which seemed permanent. Glucose tolerance tests showed normal glucose responsiveness. Gastrin on its own and epidermal growth factor on its own did not alleviate hyperglycaemia. Islet mass, islet density and pancreatic insulin content were higher in mice treated with gastrin and epidermal growth factor than in untreated mice with persisting hyperglycaemia. In normoglycaemic control mice treatment with gastrin and epidermal growth factor did not affect these parameters. We detected transitional cytokeratin-positive ductal to endocrine insulin-expressing cells and noted increased ductal but not beta-cell proliferation.. Our results show that combined treatment with gastrin and epidermal growth factor can induce sufficient regeneration of a functional islet mass to restore glucose homeostasis.

Topics: Alloxan; Animals; Blood Glucose; Body Weight; Cell Count; Cell Division; Diabetes Mellitus, Experimental; Epidermal Growth Factor; Gastrins; Glucose Tolerance Test; Immunohistochemistry; Infusion Pumps, Implantable; Insulin; Islets of Langerhans; Keratins; Male; Mice; Mice, Inbred C57BL; Organ Size; Pancreas; Pancreatic Ducts

Recent reports indicate that epidermal growth factor (EGF) plays a crucial role for graft adaptation in rat model of small bowel transplantation (SBT). The administration of EGF enhances intestinal cell proliferating rate and the recovery of mucosal structure. However, the effect of EGF on biological functions including glucose absorption in intestinal graft remains to be elucidated. SBT was performed in the two-step procedure. On the first step, intestinal graft (30-cm jejunum) from Brown Norway rats was exteriorized through abdominal wall as a Thiry-Vella loop in recipient Lewis rats for one week. On the second surgery (POD 7), recipient jejunum was replaced orthotopically by the graft, and transplanted rats were treated intraperitoneally with EGF or its vehicle for 3 days. Analyses of histology and biological functions in the graft were done at POD 14. EGF increased both levels of villus height and crypt depth in the graft of transplanted groups. EGF enhanced the glucose absorption as well as the induction of sodium glucose cotransporter 2- to 3-fold in transplanted groups. Further, EGF stimulated the activities of disaccharidase (maltase and sucrase) and the induction of dipeptide cotransporter. These results demonstrate that EGF enhances the structural and functional adaptation of intestinal grafts after SBT. EGF may be useful therapy for patients following intestinal transplantation.

Topics: Adaptation, Physiological; Animals; Blotting, Western; Body Weight; Disaccharides; Epidermal Growth Factor; Glucose; Graft Survival; Intestine, Small; Membrane Glycoproteins; Monosaccharide Transport Proteins; Rats; Rats, Inbred Lew; Sodium-Glucose Transporter 1; Statistics, Nonparametric

We have previously reported the synthesis of SMA41, a unimolecular combination of an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) of the quinazoline class and a DNA-damaging monomethyltriazene termed "combimolecule". Hydrolysis of 1-[4-(m-tolylamino)-6-quinazolinyl]-3-methyltriazene (SMA41) gives rise to an intact TKI [6-amino-4-(3-methylanilino)quinazoline; SMA52] capable of inhibiting epidermal growth factor (EGF)-induced EGFR autophosphorylation and a DNA-targeting methyldiazonium species. Herein, we showed that SMA41 blocked EGF-induced EGFR autophosphorylation by an irreversible mechanism, suggesting that it may covalently damage the receptor in these cells. More importantly, this was associated with significant inhibition of mitogen-activated protein kinase activation in A431 cells. In cells treated with [14C]SMA41, radio-high-performance liquid chromatography detection of both N7- and O6-methylguanine revealed an almost complete repair of the O6-methylguanine lesions and a greater tolerance of the N7-methylguanine adducts 24 h post-treatment. In contrast to temozolomide (a cyclic triazene used in the clinic) and the reversible inhibitor SMA52, SMA41 induced significant cell cycle arrest in S, G2, and M phases 24 h after a 2-h drug exposure. Furthermore, in vivo studies demonstrated that SMA41 was well tolerated. At 200 mg/kg, it showed approximately 2-fold greater antiproliferative activity than SMA52 in A431 cells implanted in immunocompromised SCID mice. These results suggest that the binary targeting properties of SMA41 are associated with a binary cascade of events in the cells that seem to culminate into significant growth inhibition in vitro and in vivo.

Topics: Animals; Antineoplastic Agents; Blotting, Western; Body Weight; Cell Cycle; Cell Line, Tumor; Chromatography, High Pressure Liquid; Comet Assay; DNA Damage; DNA, Neoplasm; Dose-Response Relationship, Drug; Drug Delivery Systems; Epidermal Growth Factor; Flow Cytometry; Humans; Mice; Mice, SCID; Mitogen-Activated Protein Kinases; Neoplasm Transplantation; Neoplasms; Quinazolines; Signal Transduction

Epiregulin, an epidermal growth factor family member, acts as a local signal mediator and shows dual biological activity, stimulating the proliferation of fibroblasts, hepatocytes, smooth muscle cells, and keratinocytes while inhibiting the growth of several tumor-derived epithelial cell lines. The epiregulin gene (Ereg) is located on mouse chromosome 5 adjacent to three other epidermal growth factor family members, epigen, amphiregulin, and betacellulin. Gene targeting was used to insert a lacZ reporter into the mouse Ereg locus and to ablate its function. Although epiregulin is broadly expressed and regulated both spatially and temporally, Ereg null mice show no overt developmental defects, reproductive abnormalities, or altered liver regeneration. Additionally, in contrast to previous hypotheses, Ereg deficiency does not alter intestinal cancer susceptibility, as assayed in the ApcMin model, despite showing robust expression in developing tumors. However, Ereg null mice are highly susceptible to cancer-predisposing intestinal damage caused by oral administration of dextran sulfate sodium.

Topics: Animals; Body Weight; Cell Line; Colon; Dextran Sulfate; Disease Models, Animal; Epidermal Growth Factor; Epiregulin; Epithelial Cells; Gene Targeting; Genes, Reporter; Intestinal Mucosa; Intestinal Neoplasms; Liver Regeneration; Male; Mice; Mice, Knockout; Tissue Distribution

A protective effect of breast-feeding against the development of celiac disease has been described, but the nature and effects of the actual milk components have not been established. Epidermal growth factor (EGF), a milk cytokine affecting the proliferation and differentiation of mucosal epithelial cells, was studied as to its potential protective effect on the damage of intestinal mucosa by gliadin in a model system.. Enteropathy was induced by gliadin in inbred AVN strain rat pups delivered by cesarean section, breast-fed, or hand-fed a milk formula. All experimental groups were treated with interferon-gamma (1,000 U per animal, administered intraperitoneally) after birth. Gliadin (0.5 and 3 mg) was intragastrically administered to the pups on days 0 and 3, and a 30-mg challenge dose was given on day 20 (24 hours before the termination of the experiment). One group of artificially fed pups received EGF (100 ng/ml) continuously in the diet.. Gliadin- and interferon-gamma-treated formula-fed rat pups showed villus atrophy, increase of inflammatory cells, including CD4+ T lymphocytes in the lamina propria, and damage to epithelial tight junctions and the enterocyte brush border. Morphometrically, the villus height was significantly less than in other groups. Recombinant EGF was markedly increased in the epithelial cells of injured jejunum. The intestinal mucosa of gliadin- and interferon-gamma-treated pups kept on a EGF-supplemented artificial diet resembled that of breast-fed pups.. Pathologic changes in jejunal mucosa (villus atrophy and inflammation) resembling gliadin-induced atrophy appeared on administration of interferon-gamma and gliadin to rat pups fed an artificial milk diet immediately after birth. Addition of EGF to the diet protected the rats against pathologic mucosal changes.

Topics: Animals; Animals, Newborn; Animals, Suckling; Body Weight; Celiac Disease; Disease Models, Animal; Epidermal Growth Factor; Gliadin; Jejunum; Microscopy, Electron, Scanning; Nutritional Support; Rats; Rats, Inbred Strains; Time Factors

The granular convoluted tubule (GCT) cells of the submandibular glands represent a major production site for epidermal growth factor (EGF). This study investigates EGF production in the submandibular glands in relation to beta-adrenergic stimulation. Rats were treated with isoproterenol (beta-agonist), which caused up to a 400% increase in submandibular tissue weight after 3 weeks. The weight increase coincided with marked morphologic changes, with degranulation and an apparent decrement in the number of the GCT cells. Immunostaining against EGF revealed a reduction in the number of EGF-immunoreactive cells. Concomitantly, the glandular contents of 6-kDa EGF decreased from 12.86+/-3.42 nmol/gland (mean+/-S.E.M.) in controls to 0.26+/-0.03 nmol/gland. EGF mRNA levels, expressed relative to total RNA levels, only tended to be reduced after 3 weeks as judged from RT-PCR and in situ hybridization (ISH). The isoproterenol-treated rats had increased output of EGF in the saliva, but the salivary secretion of protein was also increased. In both glandular tissue and saliva, gel filtration revealed partially processed high molecular weight forms of EGF in the isoproterenol-treated rats. These data indicate that isoproterenol treatment leads to a hyperstimulatory state of the GCT cells, which then causes depletion of the cellular stores of mature EGF, and most likely due to a shortened posttranslational transit, incomplete peptide processing.

Topics: Adrenergic beta-Agonists; Animals; Body Weight; Epidermal Growth Factor; Female; Immunohistochemistry; In Situ Hybridization; Isoproterenol; Organ Size; Protein Processing, Post-Translational; Rats; Rats, Wistar; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Saliva; Submandibular Gland

A requirement for tooth eruption is the resorption of alveolar bone. Because bone resorption is stimulated by dexamethasone both in vivo and in vitro, dexamethasone 21-phosphate, a soluble form of dexamethasone, was injected into rats to determine its effect on tooth eruption. Such dexamethasone injections accelerate the time of intra-osseous eruption in rat incisors but do not accelerate the eruption time of rat molars when injected into rats. The injections of dexamethasone 21-phosphate also accelerate the time of eyelid opening in the postnatal rats, as well as retarding growth, as measured by body weight. These effects of dexamethasone 21-phosphate parallel the effects of epidermal growth factor injections, including the absence of an effect on molar eruption. This suggests that the molecular signals for the initiation of tooth eruption (i.e., onset of bone resorption) differ between rat incisors and molars. Given that rat incisors are teeth of continuous eruption whereas rat molars are teeth of limited eruption, as are human teeth, care must be taken in extrapolating results derived from rat incisors to human dentition. In vitro, dexamethasone has no effect on the gene expression of either osteoprotegerin or epidermal growth factor in dental follicle cells derived from molars. Because osteoprotegerin expression during normal tooth eruption is transitorily inhibited early postnatally in the molar dental follicle to allow osteoclast formation, the absence of inhibition of its expression by dexamethasone could explain why dexamethasone does not accelerate eruption in molars.

Topics: Animals; Animals, Newborn; Body Weight; Dexamethasone; DNA Primers; Epidermal Growth Factor; Eyelids; Gene Expression; Glucocorticoids; Glycoproteins; Incisor; Injections, Subcutaneous; Molar; Osteoprotegerin; Rats; Rats, Sprague-Dawley; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Tooth Eruption

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) exposure produces hydronephrosis and cleft palate in mice. These responses are correlated with disruption of expression of epidermal growth factor (EGF) receptor ligands, primarily EGF and transforming growth factor-alpha (TGF-alpha), and altered epithelial cell proliferation and differentiation. This research examined the role of these growth factors in TCDD-induced teratogenicity by using wild type (WT) and knockout (-/-) mice that do not express EGF, TGF-alpha, or both EGF and TGF-alpha. Pregnant females were weighed on GD 12 and dosed by gavage with either corn oil or TCDD at 24 microg/kg, 5 ml/kg. On GD 17.5, the maternal parameters evaluated included body weight, body weight gain, liver weight (absolute and adjusted for body weight). The number of implantations, live and dead fetuses, early or late resorptions, the proportion of males, fetal body weight, fetal absolute and relative liver weight, placenta weight, incidence of cleft palate, and the severity and incidence of hydronephrosis were recorded. TCDD did not affect maternal weight gain, fetal weight, or survival, but maternal and fetal liver weights and liver-to-body weight ratios were increased in all genotypes. The WT and TGF-alpha (-/-), but not the EGF (-/-) and EGF + TGF-alpha (-/-) fetuses, developed cleft palate after exposure to 24 microg TCDD/kg. Hydronephrosis was induced by TCDD in all genotypes, with the incidence in EGF + TGF-alpha (-/-) fetuses comparable to that of the WT. The incidence and severity of this defect was substantially increased in EGF (-/-) and TGF-alpha (-/-). In conclusion, this study demonstrated that expression of EGF influences the induction of cleft palate by TCDD. Also, EGF and TGF-alpha are not required for the induction of hydronephrosis, but when either is absent the response of the fetal urinary tract to TCDD is enhanced.

Topics: Abnormalities, Drug-Induced; Administration, Oral; Animals; Body Weight; Cleft Palate; Environmental Pollutants; Epidermal Growth Factor; Female; Hydronephrosis; Liver; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Organ Size; Polychlorinated Dibenzodioxins; Pregnancy; Reproduction; Teratogens; Toxicity Tests; Transforming Growth Factor alpha

Mice lacking epidermal growth factor (EGF), transforming growth factor alpha, and amphiregulin were used to identify roles for these EGF receptor (EGF-R) ligands in gastrointestinal development and mucosal integrity.. Gastrointestinal tract development was examined in knockout mice and correlated with expression of EGF-R protein and EGF family members throughout the gut. Crossfostering experiments addressed roles of maternal- and neonatal-derived ligands in pup growth and intestinal development. Cysteamine-induced ulceration in EGF(-/-) mice was used to examine its role in mucosal cytoprotection.. Neonatal mice lacking all 3 ligands were growth retarded, even when reared by wild-type dams; conversely, lack of maternal ligands transiently impaired wild-type pup growth. Triple null neonates displayed spontaneous duodenal lesions, and ileal villi were truncated and fragile with reduced cellular proliferation in the crypts. However, maturation of digestive enzymes was unaffected. Adult EGF(-/-) mice displayed more severe lesions in response to cysteamine treatment compared with wild-type counterparts, although triple null mice were not more susceptible to dextran sulfate sodium-induced colitis, suggesting a differential role for these ligands in the injury response.. EGF-R ligands are required for development and mucosal maintenance in mouse small intestine. Both maternal and neonatal sources of growth factors are required for optimal pup growth.

Topics: Amphiregulin; Animals; Body Weight; Duodenal Diseases; Duodenum; EGF Family of Proteins; Epidermal Growth Factor; Female; Glycoproteins; Growth Disorders; Growth Substances; Intercellular Signaling Peptides and Proteins; Mice; Reverse Transcriptase Polymerase Chain Reaction; Species Specificity; Transforming Growth Factors

We determined the route of action of epidermal growth factor (EGF) [intraperitoneal (IP) versus intraamniotic administration] on adrenal development and whether its effects are mediated via the fetal hypothalamic-pituitary axis in the fetal rhesus monkey in vivo. EGF (40 microg) was administered IP (n = 9) or intraamniotic (n = 6) at 121, 123, 125, and 127 d gestation (term, approximately 165 +/- 10 d gestation). In addition, a competitive corticotropin-releasing factor antagonist ([D-phenylalanine(12), Norleucine(21,38)] corticotropin-releasing factor(12-41) to block fetal pituitary ACTH secretion; 400 microg IP) and metyrapone (11beta-hydroxylase inhibitor to block adrenal cortisol synthesis; 15 mg IP and 15 mg intraamniotic) were administered, in combination with EGF (EGF+BLOCK; 40 microg IP; n = 4 fetuses). Control fetuses (n = 6) received saline injections in an equivalent volume. On gestational d 128, a hysterotomy was performed, and fetal adrenals were collected for morphometric analyses and immunocytochemical localization of 3beta -hydroxysteroid dehydrogenase (3betaHSD) and cytochrome P-450 11beta -hydroxylase/aldosynthase. Definitive zone (DZ) width and cortical width of 3betaHSD staining were significantly greater (p < 0.05) in the EGF IP-treated fetuses compared with controls and EGF+BLOCK. With EGF IP, 3betaHSD was increased in the DZ and induced extensively in the transitional zone of the fetal adrenal cortex, and cytochrome P-450 11beta-hydroxylase/aldosynthase immunoreactivity was induced to detectable levels in the DZ. The administration of EGF+BLOCK inhibited the expression of 3betaHSD in the transitional zone, but 3betaHSD expression was still increased in the DZ and cytochrome P-450 11beta-hydroxylase/aldosynthase immunoreactivity was induced in the DZ. EGF intraamniotic administration had no significant effect on the width of the DZ or cortical width of 3betaHSD staining compared with controls. These data suggest that EGF acts via the hypothalamic-pituitary axis to modulate adrenal cortical growth and functional maturation of the transitional zone (the putative zona fasciculata), whereas EGF can act independently of the hypothalamic-pituitary axis to stimulate functional maturation of the DZ (the putative zona glomerulosa).

Topics: 3-Hydroxysteroid Dehydrogenases; Adrenal Glands; Amniotic Fluid; Animals; Body Weight; Epidermal Growth Factor; Female; Fetal Organ Maturity; Hypothalamo-Hypophyseal System; Injections, Intraperitoneal; Macaca mulatta; Organ Size; Pregnancy

Remodeling of the cerebral vasculature contributes to the pathogenesis of cerebral ischemia. Remodeling is caused by increased smooth muscle proliferation and may be due to an increase in the responsiveness of vascular cells to epidermal growth factor (EGF). Aldosterone is a risk factor for stroke, and the literature suggests it may play a role in increasing the expression of the receptor for EGF (EGFR). We hypothesized that mRNA for the EGF-stimulated pathway would be elevated in the vasculature of stroke-prone spontaneously hypertensive rats (SHRSP) and that this and experimental ischemic cerebral infract size would be reduced by aldosterone inhibition with spironolactone. We found that spironolactone treatment reduced the size of cerebral infarcts after middle cerebral artery occlusion in SHRSP (51.69 +/- 3.60 vs. 22.00 +/- 6.69% of hemisphere-infarcted SHRSP vs. SHRSP + spironolactone P < 0.05). Expression of EGF and EGFR mRNA was higher in cerebral vessels and aorta from adult SHRSP compared with Wistar-Kyoto rats. Only the expression of EGFR mRNA was elevated in the young SHRSP. Spironolactone reduced the EGFR mRNA expression in the aorta (1.09 +/- 0.25 vs. 0.56 +/- 0.11 phosphorimage units SHRSP vs. SHRSP + spironolactone P < 0.05) but had no effect on EGF mRNA. In vitro incubation of aorta with aldosterone +/- spironolactone produced similar results, suggesting a direct effect of aldosterone. Thus spironolactone may reduce the size of cerebral infarcts via a reduction in the expression of the EGFR mRNA, leading to reduced remodeling.

Topics: Aldosterone; Animals; Aorta; Basal Ganglia; Blood Pressure; Body Weight; Cerebral Cortex; Cerebral Infarction; Epidermal Growth Factor; ErbB Receptors; Genetic Predisposition to Disease; In Vitro Techniques; Infarction, Middle Cerebral Artery; Male; Mineralocorticoid Receptor Antagonists; Ophthalmic Artery; Rats; Rats, Inbred SHR; Rats, Inbred WKY; RNA, Messenger; Spironolactone; Stroke

Using the NOD mouse, a model for type 1 diabetes, we examined how reduced concentrations of epidermal growth factor (EGF) in the saliva, after onset of type 1 diabetes, affect oral wound healing. Diabetic NOD/LtJ mice on insulin therapy, prediabetic NOD/LtJ, and age- and sex-matched BALB/cJ mice were given a cutaneous tongue punch and allowed to undergo normal healing. With diabetes onset and a reduction in saliva-derived growth factor levels, the rate of tongue wound healing was reduced compared with nondiabetic NOD/LtJ and healthy BALB/cJ mice. Addition of exogenous EGF to the drinking water did not accelerate the rate of healing in BALB/cJ or prediabetic NOD/LtJ; however, diabetic NOD/LtJ mice exhibited accelerated wound healing similar to healthy mice. These results demonstrate that loss of growth factors from saliva is associated with profoundly reduced oral wound healing, suggesting that therapeutic treatment with topical delivery may be beneficial to patients with type 1 diabetes and oral wound complications.

Topics: Animals; Body Weight; Diabetes Mellitus, Type 1; Epidermal Growth Factor; Female; Homeostasis; Mice; Mice, Inbred BALB C; Mice, Inbred NOD; Organ Size; RNA, Messenger; Tongue; Wound Healing; Wounds and Injuries

The effects of in ovo peptide YY (PYY) or epidermal growth factor (EGF) administration on chick growth, yolk absorption and yolk stalk function in posthatch (0-5 days) meat-type or broiler chicks were determined. At Day 18 of incubation, treated eggs were injected into the air cell with 100 microl of either PYY (Trial 1) or EGF (Trial 2) at a dosage of 600 microg/kg egg weight. Saline-treated control eggs were injected similarly with 0.9% saline. At hatch, 200 microl of (51)Cr-labeled microspheres were injected into chick yolk sacs. Epidermal growth factor increased ileal wet weight adjusted for body weight as well as ileal serosal dry matter. Body weight, feed consumption and excreta weight per bird, and relative weights of the yolk sac, intestine and liver were significantly affected by age of the chick in both trials. Relative radioactivity of the yolk sac, yolk stalk, blood, liver, and kidneys were affected by bird age in Trial 2; however, there were no significant effects due to PYY or EGF treatments on relative radioactivity of the tissues and organs examined. These data suggest that PYY and EGF had no effect on yolk absorption or yolk stalk function through 5 days in the posthatch chick.

Topics: Animals; Body Weight; Chickens; Egg Yolk; Epidermal Growth Factor; Intestines; Liver; Organ Size; Ovum; Peptide YY; Time Factors

Fetal intrauterine growth retardation (IUGR) is one of the most common obstetric problems, with a frequency of 12% in Mexico. In the past, investigations have focused on extrinsic causes of IUGR. More recent studies have examined the intrinsic factors that cause fetal intrauterine growth. Maintenance of fetal growth has been attributed to insulin-like growth factor (IGF), epidermal growth factor (EGF) and transforming growth factor beta (TGF-beta). The objective of this study was to assess the levels of these growth factors during pregnancy and to determine whether or not low concentrations are associated with IUGR.. Nine women whose pregnancies were complicated by IUGR and a group of nine women whose pregnancies exhibited normal fetal intrauterine growth were studied. IUGR was determined by sonography and confirmed by weight at birth. Venous blood samples were taken from both groups of pregnant women at the end of each trimester. Enzyme-linked immunosorbent assays, immunoradiometric assays and radioimmunoassays were used to process samples, and the results were analysed by anova.. IGF-I levels increased in both groups during pregnancy, but the increase was lower (p < 0.001) in the IUGR group throughout pregnancy and at delivery. EGF did not show any significant changes during pregnancy. Blood TGF-beta levels varied only during the first trimester of pregnancy. The differences were not statistically significant. However, TGF-beta concentrations were higher in the pregnancies with IUGR. Women in the IUGR group were smaller than in the control group (p < 0.05), and, using the covariance test (p < 0.05), this was found to be correlated with IGF-I levels but not with EGF or TGF-beta levels.. Changes in fetal weight might be explained by the different concentrations of IGF. The structural homology between IGF-1 and insulin could mean that the presence of higher levels of IGF would result in a increased energetic metabolism that could contribute to fetal growth. EGF levels were not related to IUGR, and TGF-beta levels increased only during the first 3 months in the IUGR group. This observation correlates with the in vitro action of TGF-beta as a negative factor of growth, but as a positive support for sustaining early pregnancy. Our data illustrates that low height represents an increased risk factor for IUGR. These data also correlate with the studies involving extrinsic factors.

Topics: Adult; Body Weight; Embryonic and Fetal Development; Epidermal Growth Factor; Female; Fetal Growth Retardation; Gene Expression Regulation, Developmental; Humans; Infant, Newborn; Insulin-Like Growth Factor I; Mexico; Pregnancy; Pregnancy Trimester, First; Pregnancy Trimester, Second; Pregnancy Trimester, Third; Socioeconomic Factors; Transforming Growth Factor beta

Epidermal growth factor (EGF) is present in milk from various mammalian species, but its physiologic function in neonatal development remains unclear. Transforming growth factor-alpha (TGF-alpha) is a peptide structurally related to EGF, and its presence is detected in the developing small intestine of rats. The purpose of the present study was to examine the effect of milk-borne EGF on endogenous production of EGF and TGF-alpha in the small intestine of suckling rats. Neonatal rats were fed via gastrostomy either growth factor-free rat milk substitute (RMS) or RMS supplemented with EGF (100 ng/mL of RMS) from 8 to 12 d of age. Artificially reared rats were then compared with their dam-fed littermates. Animals fed the EGF-deficient diet RMS had markedly increased EGF and TGF-alpha mRNA levels in duodenum and ileum compared with dam-fed controls and significantly elevated total intestinal content of TGF-alpha peptide. Intestinal EGF content and EGF serum levels were significantly decreased in the RMS group compared with controls. The addition of EGF to the RMS diet normalized TGF-alpha mRNA levels in the duodenum and ileum, EGF mRNA levels in the ileum, and total intestinal TGF-alpha content and EGF serum levels to the levels measured in dam-fed littermates. Motility studies showed that enteral administration of EGF did not affect stomach emptying and intestinal transit. These studies indicate that exogenous milk-borne EGF modulates endogenous production of TGF-alpha in developing small intestine. It is likely that neither TGF-alpha nor EGF are solely responsible for small intestinal overgrowth of artificially reared neonatal rats.

Topics: Animals; Animals, Newborn; Body Weight; Epidermal Growth Factor; Female; Gastrointestinal Motility; Intestine, Small; Male; Milk; Rats; Rats, Sprague-Dawley; Transforming Growth Factor alpha

Systemic administration of epidermal growth factor (EGF) in neonatal rats results in reduced body weight gain and decreased circulating levels of IGF-I, suggesting its involvement in EGF-induced growth retardation. We investigated the effect of EGF and/or IGF-I administration for 7 days on circulating IGF-I and IGFBP levels and hepatic and renal IGF-system mRNA expression profiles in adult female rats. EGF administration (30 microg/rat/day) did not influence body weight, liver or kidney weight. In contrast, IGF-I (400 microg/rat/day) and EGF/IGF-I administration increased both body weight and kidney weight. Also, serum IGF-I and the 30 kDa IGFBPs (IGFBP-1 and -2) were significantly increased in these groups. Serum IGFBP-3 levels increased in the IGF-I group along with increased hepatic IGFBP-1 and -3 mRNA levels. In contrast, in the EGF administration group serum IGFBP-3 levels were significantly decreased; however, the mRNA levels remained unchanged. In the EGF/IGF-I administration group, serum IGF-I and IGFBP-3 levels were significantly lowered when compared with the IGF-I administration group. This was in contrast to the effect on kidney weight increase that was identical for the IGF-I and EGF/IGF-I groups. The decrease in serum IGFBP-3 was not reflected at the hepatic IGFBP-3 mRNA level. IGFBP-3 expression might be regulated at a post-transcriptional level although EGF induced IGFBP-3 proteolysis could not be demonstrated in vitro. We conclude that EGF administration reduced serum IGFBP-3 whereas IGF-I administration increased the level of IGFBP-3 and IGF-I and resulted in an increased body and kidney weight in adult female rats.

Topics: Animals; Body Weight; Epidermal Growth Factor; Female; Insulin-Like Growth Factor Binding Proteins; Insulin-Like Growth Factor I; Kidney; Liver; Rats; Rats, Wistar; RNA, Messenger

This study investigates the renal and urinary levels of epidermal growth factor (EGF) in rats under long-term treatment with alpha- or beta-adrenergic agonists. Urine samples were obtained on days 7, 14 and 21, and renal tissue samples on day 21. EGF was quantified by ELISA and tissue sections were used for immunohistochemistry and in situ hybridization. Fractional kidney weight was increased in the alpha-adrenergic agonist-treated group by 35% when compared with controls. Histological examination of the kidney revealed well-defined wedge-shaped areas of tubular dilatations and luminal amorphous material in the distal tubules. Concomitantly, reduced levels of EGF and EGF mRNA were observed, and also the urinary levels of EGF were reduced. Together, these observations indicate alpha-adrenergic treatment to affect the distal tubules. Treatment with the beta-adrenergic agonist did not change fractional kidney weight, but initially the urinary excretion of EGF was reduced. The data add further evidence to the suggestion that activity of the sympathetic nervous system influences renal homeostasis of EGF, either directly or indirectly through renal histopathological changes.

Topics: Adrenergic alpha-Agonists; Adrenergic beta-Agonists; Animals; Blood Pressure; Body Weight; Epidermal Growth Factor; Female; Immunohistochemistry; In Situ Hybridization; Isoproterenol; Kidney; Organ Size; Phenylephrine; Rats; Rats, Wistar; Time Factors

Topics: Animals; Body Weight; Epidermal Growth Factor; Glucose; Immunosuppressive Agents; Intestinal Absorption; Intestinal Mucosa; Jejunum; Male; Postoperative Period; Rats; Rats, Inbred BN; Rats, Inbred Lew; Tacrolimus; Transplantation, Homologous

The epidermal growth factor (EGF) family of peptides signals through the erbB family of receptor tyrosine kinases and plays important roles in development and tumorigenesis. Both EGF and transforming growth factor (TGF)-alpha only bind to erbB1 and activate it. The precursor of EGF is distinct from that of TGF-alpha in having eight additional EGF-like repeats. We have recently shown that the EGF precursor without these repeats is biologically active and leads to hypospermatogenesis in transgenic mice. Here we present evidence that the growth of transgenic mice widely expressing this engineered EGF precursor is also stunted. These mice were consistently born at half the normal weight and reached almost 80% of normal weight at adulthood. The mechanism involved a reduction of serum insulin-like growth factor-binding protein-3. Chondrocyte development in the growth plate was affected, and osteoblasts accumulated in the endosteum and periosteum. Besides these novel findings on the in vivo effects of EGF on bone development, we observed no sign of tumor formation in our transgenic animals. In contrast to previous reports on TGF-alpha transgenic mice, we show that the biological functions of EGF and TGF-alpha are clearly distinct.

Topics: Actins; Animals; Body Weight; Bone Development; Epidermal Growth Factor; Growth Disorders; Hepatitis, Animal; Humans; Insulin-Like Growth Factor Binding Protein 3; Liver; Mice; Mice, Transgenic; Osteoblasts; Promoter Regions, Genetic

Cholecystokinin (CCK) is a hormone with well-known secretory and trophic effects on the pancreas. This also is true for epidermal growth factor (EGF), which acts in a paracrine and autocrine way. The aim was to study the influence of CCK on cell proliferation in rat pancreas with special reference to the expression of EGF, the EGF receptor, and phosphorylated tyrosine. Twenty-four male Sprague-Dawley rats received either one single injection, or injections twice daily for 3 days of 6 microg sulfated CCK-8 (CCK-8S) subcutaneously in the neck. The same number of rats received injections of 1% bovine serum albumin (BSA) in the same way. The rats were killed 1, 3, or 6 hours after the last injection. One hour before killing, they received 50 mg/kg of bromodeoxyuridine (BrdU) intraperitoneally. Plasma was collected for analysis of CCK. The pancreas was dissected, and in situ hybridization using a probe for EGF mRNA was performed for semiquantification of gene expression. Immunocytochemistry using antibodies against the EGF receptor and phosphotyrosine was performed to examine the expression of the proteins, and against BrdU for measuring the cell proliferation. A single injection of CCK-8S led to hyperCCKemia at 1 and 3 hours afterward. After 6 hours, plasma CCK had returned to the same levels as in control rats. The cell proliferation was unaffected. The rats that received CCK-8S injections for 3 days still had hyperCCKemia 6 hours after the last injection. The cell proliferation was increased by CCK, as indicated by the BrdU labeling. However, neither body weight nor pancreatic weight was affected. In controls, EGF was expressed all over the gland, but its receptor and phosphotyrosine were expressed only in ductal cells and in the islet cells of endocrine pancreas. There was no difference in the pancreatic staining of EGF, its receptor, or phosphotyrosine at the different time points studied. There was no difference in the staining of EGF and its receptor between CCK-8S- and BSA-treated animals, but phosphotyrosine staining was detectable in acinar cells after 3 days of CCK-8S injections. Thus CCK-8S causes hyperCCKemia with ensuing enhanced cell proliferation in rat pancreas. This effect on the cell proliferation seems to be a direct effect of CCK and not mediated by changes in the tissue levels of EGF or its receptor.

Topics: Animals; Body Weight; Bromodeoxyuridine; Cholecystokinin; Epidermal Growth Factor; ErbB Receptors; Immunohistochemistry; In Situ Hybridization; Male; Organ Size; Pancreas; Phosphotyrosine; Rats; Rats, Sprague-Dawley

We have previously reported that systemic epidermal growth factor (EGF) treatment in rats reduces the amount of adipose tissue despite an unaltered food intake. The mitochondrial uncoupling proteins (UCP2 and UCP3) are thought to uncouple the respiratory chain and thus to increase energy expenditure. In order to find out whether the UCP system was involved in the EGF-induced weight loss, the effects of EGF on UCP2 and UCP3 in adipose tissue and skeletal muscle were investigated in the present study. Eight rats were treated with placebo or EGF (150 microg/kg/day) for seven days via mini-osmotic pumps. The EGF-treated rats gained significantly less body weight during the study period than the placebo-treated animals and had significantly less adipose tissue despite a similar food intake. The placebo group and the EGF group had similar UCP2 mRNA expression (in both adipose tissue and skeletal muscle), whereas the EGF-treated group compared to the placebo group had significantly higher UCP3 mRNA expression in both skeletal muscle (3.76 +/- 0.90 vs 8.41 +/- 0.87, P < 0.05) and in adipose tissue (6.38 +/- 0.71 vs 12.48 +/- 1.79, P < 0.05). In vitro studies with adipose tissue fragments indicated that the EGF effect probably is mediated indirectly as incubations with EGF (10 microM) were unable to affect adipose tissue UCP expression, whereas incubations with bromopalmitate stimulated both UCP2 and UCP3 mRNA expression twofold. Thus, EGF treatment in vivo was found to enhance UCP3 mRNA expression in both adipose tissue and skeletal muscle, which may indicate that the EGF effect on body composition might involve up-regulation of UCP3 in skeletal muscle and adipose tissue.

Topics: Adipose Tissue; Animals; Body Weight; Carrier Proteins; Eating; Epidermal Growth Factor; Fat Body; Ion Channels; Male; Membrane Transport Proteins; Mitochondrial Proteins; Muscle, Skeletal; Proteins; Rats; Rats, Wistar; RNA, Messenger; Uncoupling Protein 2; Uncoupling Protein 3

A major contributor to the development and progression of ischemia-reperfusion (IR)-induced acute renal failure (ARF) is the loss of functioning tubular epithelial cells by means of various cell deletion or death processes. Although the term "acute tubular necrosis" is still used to describe the pathology of ARF, this is a misnomer because apoptotic cell death, as well as necrosis, occurs [1, 2] along with desquamation and loss of viable epithelial cells [3]. Apoptosis was first described in renal disease in 1987 in an animal model of hydronephrosis [4]. In ARF, with reference to only the death processes, the relative contribution of necrosis or apoptosis possibly depends on the extent of the initiating events. For example, after prolonged total renal ischemia, necrosis or "accidental cell death" occurs from the resultant negation of the cell's energy and protein levels. In apoptosis, the cells use their own energy processes and proteins to die, and often the initiating ischemia is more mild [5]. Finally, despite prolonged ischemia, within the heterogeneous renal cell populations there are those that are more sensitive to ischemia, such as the proximal straight tubule and to some extent the thick ascending limb (TAL) of the loop of Henle. It may be hypothesized that these cells tend to undergo necrosis in comparison with the less sensitive segments that undergo apoptosis. Because apoptosis is gene driven, its identification is important because of the possibility of its modulation via molecular controls. However, despite these new concepts of ARF, patient death remains high, at approximately 30 to 50% of ARF cases. Recovery from ARF depends not only on the replacement or regeneration of cells deleted by death, the theme of many recent studies, but also on protection of cells from death. Both processes are dependent on many of the cellular and molecular controls that have evolved in multicellular organisms to manage normal development, differentiation and growth processes, but that then become involved in the pathogenesis and progression of many renal diseases, including ARF.

Topics: Acute Kidney Injury; Animals; Apoptosis; bcl-X Protein; Body Weight; Cell Division; Cell Survival; Epidermal Growth Factor; Epithelial Cells; Insulin-Like Growth Factor I; Loop of Henle; Male; Necrosis; Proliferating Cell Nuclear Antigen; Proto-Oncogene Proteins c-bcl-2; Rats; Rats, Sprague-Dawley; Regeneration; Reperfusion Injury; Transforming Growth Factor beta

Breast cancer is one of the common cancers and is a leading cause of cancer mortality in women. The TG.NK transgenic mouse line on FVB strain background expresses the c-neu oncogene under the control of a MMTV promoter in mammary tissue and appears to be a useful animal model for evaluation of strategies to delay or prevent mammary cancer. Fiber-rich nonpurified diet (NTP-2000) and some retinoid analogues have delayed mammary cancer in the TG.NK model. Four week old hemizygous TG.NK female mice with MMTV/c-neu (erbB2) activated oncogene were fed NTP-2000 diet containing the retinoid analogue 4-hydroxyphenylretinamide (4-HPR) at 7 mmol/kg or the arotinoid Ro 40-8757 at 1.5 and 2.5 mmol/kg for 26 weeks. The 4-HPR at 7 mmol/kg diet delayed the development of palpable tumors up to 24 weeks, but by 26 weeks, the incidence markedly increased and was closer to the NTP-2000 diet control group. However, the 4-HPR diet markedly decreased the average weight of the tumors at 26 weeks with no decrease in multiplicity. The 4-HPR also caused significant increase in liver weights without an effect on body weight. Arotinoid Ro 40-8757 caused marked decrease in the number and branching of mammary ducts, and inhibited mammary tumor development with significant decrease in the incidence, multiplicity, and tumor weights compared to the NTP-2000 diet control. Arotinoid also caused a significant dose-related increase in liver weights without a significant effect on body weights. At the doses tested, the arotinoid but not 4-HPR decreased the circulating levels of IGF-1. However, there was no association between the IGF-1 levels and the size, incidence, or absence of tumors when evaluated for any treatment group or for all mice in the study irrespective of treatment. The oncogene erbB2 (c-neu) and the growth factor EGF expression were more prominent in the small tumors of the mice treated with arotinoid than in the larger tumors of the control group. PCNA staining was observed in areas where there was high erbB2 and EGF staining. The delay in onset of mammary tumors by the above retinoid analogues may be related to the delay in development of mammary glands.

Topics: Animals; Body Weight; Cell Transformation, Neoplastic; Diet; Epidermal Growth Factor; Female; Genes, erbB-2; Mammary Glands, Animal; Mammary Neoplasms, Experimental; Mice; Mice, Transgenic; Retinoids

Topics: Animals; Body Weight; Epidermal Growth Factor; Glucose; Intestinal Absorption; Intestine, Small; Rats; Rats, Inbred Lew; Transplantation, Isogeneic; Water

Systemic treatment with epidermal growth factor (EGF) in neonatal rats reduces circulating levels of insulin-like growth factor I (IGF-I) and causes somatic growth retardation. In this study, we investigated the effects of EGF treatment on the IGF system and on visceral organ growth and longitudinal growth in mature rats. We treated female Wistar rats for 0 (n = 16), 1 (n = 8), 2 (n = 8), 3 (n = 8), or 4 (n = 8) weeks with subcutaneous EGF (150 microg/kg/day). The animals were weighed once a week. At sacrifice, various viscera were removed and weighed. Blood and serum samples obtained at sacrifice were analysed for growth hormone (GH), IGF-I, IGF binding proteins (IGFBPs) and various routine parameters. EGF treatment increased the total body weight. All parts of the gastrointestinal tract, the liver, the pancreas, the spleen, the bladder, the suprarenal glands and the ovaries increased proportionately more in weight than the increase in total body weight; the heart and the kidneys increased proportionately in weight whereas the weight of the perirenal fat was reduced. There were no changes in tail length but the mean length of the tibia was slightly increased in the group treated for 4 weeks with EGF. Circulating GH was unchanged but IGF-I and IGFBP-3 were reduced approximately 25 and 45%, respectively, in all EGF treated groups. There were no changes in the hepatic content of IGF-I and IGFBPs. In conclusion, systemic EGF treatment causes visceral growth concomitant with reduced circulating levels of IGF-I and IGFBP-3 in mature female rats.

Topics: Animals; Blood Chemical Analysis; Body Weight; Digestive System; Epidermal Growth Factor; Female; Growth Hormone; Insulin-Like Growth Factor Binding Protein 3; Insulin-Like Growth Factor Binding Proteins; Insulin-Like Growth Factor I; Lipids; Liver; Organ Size; Ovary; Rats; Rats, Wistar; Serum Albumin; Time Factors; Viscera

Antagonists of bombesin/gastrin-releasing peptide (BN/GRP) have been developed to inhibit the stimulatory effects of BN/GRP on the mitogenesis of tumor cells such as human small-cell lung carcinoma (SCLC). The mode of action of these antagonists is not completely understood. In this study, we evaluated the effect of BN/GRP antagonist RC-3095 on receptors for BN/GRP and epidermal growth factor (EGF) in H-128 human SCLC line xenografted into nude mice. Treatment with RC-3095, administered s.c. at a dose of 20 microg/day per animal for 4 weeks caused a 70% reduction in tumor volume and weight. Membrane receptors for BN/GRP and EGF were characterized in untreated and treated animals. In the control group, [125I-Tyr4]BN was bound to a single class of specific, high affinity binding sites with a dissociation constant (Kd) = 6.55 +/- 0.93 nM and maximal binding capacity (Bmax) = 512.8 +/- 34.8 fmol/mg membrane protein. Therapy with RC-3095 decreased the concentration of BN/GRP receptors on H-128 SCLC tumor membranes. Specific, high affinity binding sites for EGF with Kd = 1.78 +/- 0.26 nM and Bmax = 216.8 +/- 19.6 fmol/mg membrane protein were also found on the untreated H-128 SCLC tumors. Treatment with RC-3095 significantly decreased Bmax of receptors for EGF. Our results indicate that the suppression of growth of H-128 SCLC by BN antagonist RC-3095 is accompanied by a decrease in the number of receptors for both BN/GRP and EGF. These observations are in agreement with the results obtained in other experimental cancers. The findings on antagonist RC-3095 reinforce the view that both BN/GRP and EGF receptors participate in a cascade of events involved in the growth of SCLC and other cancers. Although the complete mechanisms of action of antagonist RC-3095 remain to be elucidated, the antitumor effect could be the result of the fall in the EGF receptor number, which might lead to a decrease in EGF receptor autophosphorylation.

Topics: Animals; Antineoplastic Agents; Body Weight; Bombesin; Carcinoma, Small Cell; Down-Regulation; Epidermal Growth Factor; ErbB Receptors; Humans; Lung Neoplasms; Male; Mice; Mice, Nude; Neoplasm Transplantation; Peptide Fragments; Protein Binding; Receptors, Bombesin; Transplantation, Heterologous; Tumor Cells, Cultured

Renal enlargement is a characteristic feature of human and experimental diabetes mellitus that may be predictive of subsequent nephropathy. In the streptozotocin diabetic rat kidney growth rapidly follows the induction of experimental diabetes but the mechanisms responsible for this growth are poorly understood. Epidermal growth factor (EGF) is a potent mitogen for renal tubular cells. Thirty one male Sprague-Dawley rats aged 13 weeks were randomised to receive either streptozotocin (diabetic, n = 20) or buffer (control, n = 11). Animals were studied on days 1, 3, 5 and 7 following streptozotocin. Diabetes was associated with a 3-fold increase in urinary EGF excretion (223 +/- 15 vs 59 +/- 5 ng/day, mean +/- SEM, diabetic vs control, p < 0.0001) and 3-6 fold increase in renal EGF mRNA relative to controls (p < 0.001). A transient rise in kidney EGF protein was noted on day 1. There was no difference between diabetic and control animals with regard to intrarenal sites of EGF expression or in plasma EGF. These data suggest that the increased urinary EGF excretion in diabetic animals is the result of enhanced local production and that EGF is not stored for a prolonged period within renal tubular cells but is released following its synthesis. In the context of the known intrarenal actions of EGF this growth factor may play a role in the pathogenesis of diabetes related kidney growth.

Topics: Animals; Body Weight; Diabetes Mellitus, Experimental; Epidermal Growth Factor; Humans; In Situ Hybridization; Kidney; Kidney Cortex; Kidney Medulla; Male; Organ Size; Rats; Rats, Sprague-Dawley; Reference Values; RNA, Messenger; Time Factors; Transcription, Genetic

The renin-angiotensin system plays an important role in renal growth and development: exposure of the fetus or neonate to angiotensin-converting enzyme (ACE) inhibitors increases mortality and results in growth retardation and abnormal renal development. This study was designed to investigate the effects of ACE inhibition in the neonatal rat on the expression of genes known to modulate renal cellular proliferation, cell interactions, and extracellular matrix. Newborn rat pups were treated with enalapril (30 mg/kg/d) or vehicle for 14 d, and kidneys were removed for Northern analysis of mRNA for transforming growth factor-beta1 (TGF-beta1), prepro epidermal growth factor (EGF), clusterin, and renin. Distribution of TGF-beta1, EGF, and clusterin was also determined by immunohistochemistry. Enalapril treatment resulted in 40% mortality by d 14, reduced body and kidney weight, decreased glomerular area, and caused tubular dilatation (p < 0.05 versus vehicle group). Enalapril decreased renal TGF-beta1 and EGF mRNA expression, and increased renal clusterin and renin expression (p < 0.05). Renal tubular immunoreactive EGF was decreased, and clusterin was increased by enalapril treatment. These results indicate that ACE inhibition in the developing kidney reduces the renal expression of critical growth factors, which may account for renal growth impairment. Clusterin expression may increase either due to blockade of tonic angiotensin-mediated inhibition, or as an adaptive response to renal ischemia.

Topics: Angiotensin II; Angiotensin-Converting Enzyme Inhibitors; Animals; Animals, Newborn; Body Weight; Clusterin; Enalapril; Epidermal Growth Factor; Glycoproteins; Growth Substances; Kidney; Kidney Glomerulus; Kidney Tubules; Molecular Chaperones; Organ Size; Protein Precursors; Rats; Rats, Sprague-Dawley; Transforming Growth Factor beta

The control of intestinal epithelial growth is regulated by interactions of growth factors in various cellular compartments of the small and large bowel. Little information is available on the intestinal growth response to combinations of growth factors. We studied the intestinotrophic properties of a dipeptidyl peptidase IV resistant glucagon-like peptide 2 (GLP-2) analog, human [Gly2]GLP-2 (h[Gly2]GLP-2), as well as of epidermal growth factor (EGF), long [Arg3]insulin-like growth factor I (LR3IGF-I), [Gly1]IGF-II, and human growth hormone (hGH), administered by subcutaneous injection alone or in combination in mice. At the doses tested, h[Gly2]GLP-2 was the most potent agent for increasing small and large bowel mass. Mice treated with h[Gly2]GLP-2 and either GH or IGF-I exhibited greater increases in histological parameters of small intestinal growth than did mice treated with h[Gly2]GLP-2 alone. Administration of all five growth factors together induced significant increases in crypt plus villus height and in small and large bowel length and weight. The results of these experiments define regional differences in both the cellular targets and relative activities of intestinotrophic molecules and raise the possibility that selective growth factor combinations may be useful for enhancement of intestinal adaptation in vivo.

Topics: Animals; Body Weight; Drug Interactions; Epidermal Growth Factor; Female; Glucagon-Like Peptide 2; Glucagon-Like Peptides; Growth Substances; Human Growth Hormone; Humans; Ileum; Insulin-Like Growth Factor I; Insulin-Like Growth Factor II; Intestinal Mucosa; Intestine, Large; Intestine, Small; Jejunum; Mice; Organ Size; Peptides; Rats

Using immunohistochemistry, Northern blotting and a semi-quantitative PCR technique, epidermal growth factor (EGF), transforming growth factor-alpha (TGF-alpha) and epidermal growth factor receptor (EGFR) expression were studied in the pancreas of N-nitrosobis(2-oxopropyl)-amine (BOP)-treated hamsters. After initiation pancreatic carcinogenesis was modulated by a high fat diet or by injections with the cholecystokinin analogue caerulein. Autopsies were performed 6 and 12 months after the last injection with BOP. Immunohistochemistry revealed a weak expression of TGF-alpha in nomal acinar cells and a stronger expression in ductular and centro-acinar cells. Over-expression of TGF-alpha was observed in advanced putative preneoplastic lesions (classified as borderline lesions) and in ductular adenocarcinomas. EGFR immunoreactivity was present only in ductular adenocarcinomas. EGF peptide expression was observed both in acinar and ductular normal and tumorous cells and the level of expression did not change significantly during carcinogenesis. Moreover, the post-initiation treatments did not cause differences in EGF, TGF-alpha or EGFR peptide or mRNA levels, except for a significantly lower expression of TGF-alpha mRNA in hamsters fed a high fat diet when compared with those fed a low fat diet. TGF-alpha mRNA levels increased, whereas EGF mRNA levels decreased significantly in total pancreatic homogenates of BOP-treated hamsters in comparison with untreated controls. Also, in ductular adenocarcinomas TGF-alpha and EGFR (but not EGF) mRNA levels were significantly higher than in normal pancreatic homogenates. In pancreatic homogenates obtained 6 months after the last BOP injection, these differences were less pronounced in comparison with those obtained after 12 months. The present results indicate that TGF-alpha (but not EGF) might act in a paracrine or autocrine manner in pancreatic tumours in BOP-treated hamsters via simultaneously expressed EGFR. However, TGF-alpha, EGF and EGFR do not seem to be involved in the modulating effects of a high fat diet or caerulein treatment on pancreatic carcinogenesis in BOP-treated hamsters.

Topics: Adenocarcinoma; Animals; Blotting, Northern; Body Weight; Carcinogens; Cricetinae; Epidermal Growth Factor; ErbB Receptors; Immunohistochemistry; Mesocricetus; Nitrosamines; Organ Size; Pancreas; Pancreatic Neoplasms; Polymerase Chain Reaction; Transforming Growth Factor alpha

In neonatal rats, systemic administration of epidermal growth factor (EGF) results in reduced body weight gain and decreased levels of circulating IGF-I, which suggests that it be involved in the EGF-induced growth retardation. We investigated the effect of 4 weeks of EGF administration on circulating free and total IGF-I and IGF-binding proteins (IGFBPs) in adult rats treated with saline (controls), 30 (low dose group) and 150 (high dose group) microgram/kg/day EGF. Serum IGF-I was determined in ultrafiltrates (free) and acid-ethanol extracts (total), and serum IGFBPs using Western ligand blotting, which yielded four distinct molecular bands. The IGFBPs were tentatively identified as IGFBP-3 (a double band at 42 and 38 kDa), IGFBP-1 and/or IGFBP-2 (a single band at 30 kDa) and IGFBP-4 (a single band at 24 kDa). EGF administration did not change the body weight, tibia length, or liver, heart and lung weight. In contrast, serum total IGF-I and IGFBP-3 decreased dose-dependently: total IGF-I averaged 1470 +/- 100 micrograms/l (controls; mean +/- SEM), 1030 +/- 60 micrograms/l (low dose group; P < 0.005) and 760 +/- 40 micrograms/l (high dose group; P < 0.005), whereas differences between IGFBP-3 levels reached significance (P < 0.05) between controls and high dose rats, only. When compared to controls, levels of IGFBP-1 and/or IGFBP-2 were increased in the low dose group (P < 0.05), but unchanged in the high dose group. IGFBP-4 was unaffected by EGF. Free IGF-I averaged 74 +/- 6 micrograms/l in controls, and was reduced to 35 +/- 6 micrograms/l (low dose group; P < 0.005) and 57 +/- 5 micrograms/l (high dose group; P < 0.05). Free IGF-I was inversely correlated (r = -0.49, P < 0.05) with IGFBP-1 and/or IGFBP-2. We conclude that in adult rats prolonged EGF administration has a marked depressing effect on circulating total and free IGF-I. Nevertheless, we did not observe any somatic growth retardation.

Topics: Animals; Blotting, Western; Body Weight; Dose-Response Relationship, Drug; Electrophoresis, Polyacrylamide Gel; Epidermal Growth Factor; Growth Hormone; Insulin-Like Growth Factor Binding Protein 1; Insulin-Like Growth Factor Binding Protein 2; Insulin-Like Growth Factor Binding Protein 3; Insulin-Like Growth Factor I; Insulin-Like Growth Factor II; Male; Organ Size; Radioimmunoassay; Rats; Rats, Wistar; Time Factors

This study was to investigate whether epidermal growth factor (EGF) may induce any long-term effect on pancreatic exocrine function in vivo as well to evaluate the chronic effects of EGF on pancreatic growth in rats. Rats were treated with EGF (10 micrograms/kg) for 5 or 7 days. EGF infused intravenously (2 micrograms/kg/h) in anaesthetized and pretreated rats for 5 or 7 days with EGF caused a slight decline flow rate after 1 h of EGF infusion compared to control values. In contrast, EGF evoked a increase in amylase secretion. This stimulatory effect was much larger in EGF-pretreated rats for 7 days, whereas the total protein output was unchanged. The trophic parameters which include pancreatic weight, total protein and total contents of DNA and RNA relative to body weight were not significantly different in any treated group. Only the pancreatic amylase content was increased significantly after 7 days of treatment with EGF. The present study fails to observe a stimulatory role of EGF on pancreatic growth in rats, but may participate in the regulation of pancreatic exocrine function in vivo.

Topics: Amylases; Animals; Body Weight; DNA; Epidermal Growth Factor; Female; Male; Organ Size; Pancreas; Pancreatic Juice; Rats; Rats, Wistar; RNA

In this study, we determined in vivo morphologic effects of continuous intravenous infusion of recombinant human epidermal growth factor (EGF) in adult Wistar rats. The EGF used consisted of the amino acid residues 1-48 of the human 53-amino-acid EGF molecule, purified from transfected Escherichia coli. Doses of 25, 100, or 250 micrograms/kg body weight were administered using Harvard digital syringe infusion pumps for 4 weeks. At necropsy, the submandibular salivary glands, Harderian glands, liver, kidneys (females only), and ovaries were enlarged and urinary bladders were thickened in 100- and 250-micrograms/kg rats. Numerous tissues of the 100- and 250-micrograms/kg rats contained hyperplastic epithelial cells, and selected organs also had mesenchymal cell proliferation. Epithelial proliferation was most pronounced in the trachea, nasal cavity, nasolacrimal duct, tongue, stomach, small intestine, large intestine, urinary tract, salivary gland ducts, and Harderian gland. Periportal hepatocytes were hypertrophic, correlating with increased liver weight. In addition, mesenchymal cell proliferation was evident in the gastric mucosa lamina propria and in heart valves in 100- and 250-micrograms/kg rats. Increased ovarian weight correlated with increased number and size of corpora lutea and an increased incidence of luteal cysts. Continuous systemic exposure of adult Wistar rats to high doses of EGF resulted in generalized epithelial hyperplasia and tissue-selective mesenchymal proliferation.

Topics: Amino Acid Sequence; Animals; Body Weight; Cell Count; Digestive System; Epidermal Growth Factor; Female; Gastrins; Humans; Hyperplasia; Infusions, Intravenous; Male; Molecular Sequence Data; Organ Size; Rats; Rats, Wistar; Recombinant Proteins; Respiratory System; Urogenital System

We investigated the effect of epidermal growth factor (EGF) on amino acid transport in the rat placenta and the hormonal and nutritional regulation of hepatic expression of epidermal growth factor receptor (EGFR). Fetuses born to maternal rats administered EGF were larger than control fetuses, while fetuses born to mothers administered EGF antibody were smaller than controls. The fetomaternal amino acid concentration ratio (fetal blood/maternal blood) was higher in the EGF-treated group than in the control group, and was lower in the EGF antibody-treated group. EGF treatment stimulated 14C-aminoisobutyric acid, isoleucine and alanine uptake by placental explants as did treatment with insulin-like growth factor-1 and insulin, which have been reported to stimulate the active amino acid transport. Thus, EGF promoted amino acid transport in the rat placenta and influenced fetal growth as a result. In addition, retinol induced a 170% increase of EGF binding to rat hepatocytes and insulin induced a 120% increase of EGF binding, while amino acids (isoleucine and serine) had no effect on EGF binding. This result indicated that there is hormonal regulation of EGF binding to hepatocytes and that changes of some hormone levels may affect hepatic EGFR expression.

Topics: Alanine; Amino Acids; Aminoisobutyric Acids; Animals; Antibodies; Binding, Competitive; Biological Transport; Body Weight; Dose-Response Relationship, Drug; Epidermal Growth Factor; ErbB Receptors; Female; Insulin; Insulin-Like Growth Factor I; Iodine Radioisotopes; Isoleucine; Litter Size; Liver; Maternal-Fetal Exchange; Organ Culture Techniques; Placenta; Pregnancy; Radioligand Assay; Rats; Rats, Wistar

1. The adult spontaneously hypertensive Lyon rats (LH strain) exhibited increased maximal epidermal growth factor (EGF) binding in freshly prepared kidney and aortic tissue membranes compared with age-matched normotensive (LN) or hypotensive (LL) strains. However, the binding affinity of the receptors to EGF was the same in all the three strains studied. These findings indicate an increased number of EGF receptors (EGFR) in the hypertensive LH strain. 2. Protein tyrosine kinase activity associated with the EGFR was also elevated in the LH strain compared with LN or LL strains, indicating that these receptors are functionally active. 3. There was a correlation between maximal EGF binding by aortic membranes and blood pressure in individual animals (r = 0.55; P < 0.001). 4. Taken together with previously reported similar findings in other models of genetic hypertension, the present results suggest a possible role for increased levels of EGFR in the development and maintenance of genetic hypertension.

Topics: Analysis of Variance; Animals; Aorta; Blood Pressure; Body Weight; Epidermal Growth Factor; ErbB Receptors; Kidney; Protein-Tyrosine Kinases; Rats; Rats, Inbred SHR

Growth factors such as insulin-like growth factor-1 (IGF-1), epidermal growth factor (EGF), and hepatocyte growth factor have been shown to accelerate the recovery from postischemic acute renal failure (ARF) with a concomitant increase in DNA synthesis. Interactions between growth factors have been demonstrated in a number of in vitro studies. This study examined the effect of exogenous IGF-1 on the DNA synthesis and EGF receptor (EGF-R) activation in postischemic rat kidneys. Thirty minutes after the relief of 30-minute total occlusion of the left renal artery in anesthetized 225 to 300 gm Sprague-Dawley rats, either IGF-1 (75 micrograms/kg) or normal saline solution (NS, 0.2 ml) was given by intravenous bolus, followed by twice daily subcutaneous injections of IGF-1 (50 micrograms/kg) or 0.2 ml NS for 4 days, respectively, in IGF-1-Tx) and NS treated (NS-Tx) groups (n = 8 each). On the day after the completion of treatment, inulin clearance (ml/kg/min) of the postischemic kidneys in the IGF-1-Tx group was significantly higher (p < 0.01) than inulin clearance of kidneys in the NS-Tx group. This was associated with improved kidney morphology. IGF-1 treatment also enhanced the labeling index of 5-bromo-2'-deoxyuridine (percent of stained tubule cells), a marker for active DNA synthesis, in the outer medulla of postischemic kidneys at 1 day and 2 days after the injury. EGF-R tyrosine phosphorylation (which reflects receptor activation) increased in postischemic kidneys in both NS-Tx (n = 5) and IGF-1-Tx (n = 3) groups 1 day after the injury as compared with nonischemic contralateral kidneys. In the IGF-1-Tx group there was also increased iodine 125-labeled EGF binding and EGF-R protein. Our results demonstrate a beneficial effect of IGF-1 on postischemic ARF. Furthermore, they suggest that EGF-R activation is involved in tubular regeneration and that IGF-1 may enhance EGF-R activation by increasing EGF-R expression.

Topics: Acute Kidney Injury; Analysis of Variance; Animals; Blood Pressure; Body Weight; DNA; Epidermal Growth Factor; ErbB Receptors; Insulin-Like Growth Factor I; Iodine Radioisotopes; Ischemia; Kidney Medulla; Kidney Tubules; Male; Phosphotyrosine; Rats; Rats, Sprague-Dawley; Regeneration; Renal Circulation; Tyrosine

Expression of transforming growth factor-alpha (TGF-alpha) and epidermal growth factor (EGF) was studied in normal pancreatic tissue and in (pre)neoplastic pancreatic lesions of azaserine-treated rats. They were given either a low fat, high fiber (low caloric) diet, to inhibit carcinogenesis, or a low fat diet combined with injections of the cholecystokinin analog caerulein to enhance carcinogenesis. The control groups, maintained on a low fat diet, were injected with azaserine or were not treated at all. Autopsy was performed at 6 and 15 months after the last azaserine injection. After both 6 and 15 months immunohistochemistry revealed a weak expression of EGF and TGF-alpha peptides in the acinar cells, and a stronger expression in the ductular and centroacinar cells. TGF-alpha peptide expression was reduced in both putative preneoplastic and neoplastic acinar cell lesions, but no differences in EGF peptide expression were observed between the various stages of exocrine pancreatic carcinogenesis. After 16 months an increase in TGF-alpha mRNA due to treatment with azaserine was detected by semi-quantitative PCR in total pancreatic homogenates, whereas EGF mRNA expression had decreased. TGF-alpha mRNA levels in macroscopically isolated tumors were significantly lower, but EGF mRNA levels were significantly higher, than in total pancreatic homogenates from azaserine-treated rats. Furthermore, EGF and TGF-alpha mRNA levels in isolated tumors did not differ significantly from mRNA levels in non-carcinogen-treated rats. Neither with immunohistochemistry nor with PCR were differences in EGF or TGF-alpha expression observed due to either inhibition or stimulation of carcinogenesis. It is concluded that putative preneoplastic acinar cell lesions induced in rat pancreas by azaserine may develop into acinar adenocarcinomas independently of TGF-alpha and EGF. The results suggest involvement of these growth factors at the early stage of the carcinogenic process, during the initiation of normal acinar cells into putative preneoplastic cells. However, modulation of azaserine-induced pancreatic carcinogenesis by cholecystokinin or a low fat, high fiber (caloric restricted) diet appeared not to be regulated by EGF or TGF-alpha.

Topics: Animals; Azaserine; Base Sequence; Body Weight; Carcinogens; Ceruletide; Cocarcinogenesis; Diet, Fat-Restricted; Dietary Fiber; Drug Synergism; Energy Intake; Epidermal Growth Factor; Immunohistochemistry; Male; Molecular Sequence Data; Organ Size; Pancreas; Pancreatic Neoplasms; Polymerase Chain Reaction; Rats; Rats, Wistar; RNA, Messenger; Transforming Growth Factor alpha

Metformin (MET) is known to increase several biological effects of insulin (INS), but there is no information concerning its direct effects on protein synthesis. We studied the action of MET on albumin production by primary cultures of freshly isolated rat hepatocytes, alone or in combination with various agonists: INS, IGF-1, EGF, thyroxin, and dexamethasone. While having no effect alone, MET in vitro potentiates the effects of INS, IGF-1, and EGF. When this increasing effect toward INS was studied over a broad concentration range, MET appeared to improve low-acting INS levels and to intensify the maximal INS effects. In contrast, MET did not change the production of albumin stimulated by thyroxin or dexamethasone. Animals chronically pretreated with MET in vivo showed a higher yield of isolated hepatocytes, better attachment, and especially higher viability after liver perfusion and during cell culture. This may largely explain why basal albumin rates were higher than in in vitro-treated cells. The effect of MET in the presence of the agonists exhibited the same agonist-specificity as in vitro. Our data provide new insights into the pharmacology of MET by showing that hepatic protein synthesis is increased by MET and INS. From the specificity of action of MET towards INS, IGF-1, and EGF (but not thyroxin or dexamethasone), we hypothesize that this biguanide may act on intracellular pathways located between membrane receptors and sites of branching in the signaling cascades shared by these agonists.

Topics: Albumins; Animals; Body Weight; Cell Survival; Cells, Cultured; Epidermal Growth Factor; Insulin; Insulin-Like Growth Factor I; Liver; Male; Metformin; Rats; Rats, Wistar; Time Factors

The effects of gonadectomy on the epidermal growth factor (EGF) concentrations in the gastrointestinal tract of CD-1 mice were studied. The EGF concentrations in the gastrointestinal tissues were always higher in males than in females. Gonadectomy led to a decrease in the EGF concentration in males, and an increase in females. Gonadectomy with sialoadenectomy led to a decrease in the EGF concentrations in the gastrointestinal tract of both sexes; the most significant effect being observed in the stomach. Orchidectomy led to a decrease in total body weight, and to a significant decrease in the weight and the protein concentration (ng.g-1 wet weight of tissue) of the submandibular gland, but had no significant effect on the other tissues of the gastrointestinal tract of male mice. Body, tissue weights, and protein concentrations did not change with oophorectomy. This study shows that male and female gonads have a profound effect on the EGF content of the tissues of the gastrointestinal tract and suggests that the submandibular gland also influences the EGF concentration in gastrointestinal tissues in mice.

Topics: Animals; Body Weight; Castration; Digestive System; Epidermal Growth Factor; Female; Male; Mice; Mice, Inbred Strains; Time Factors

To define the role that thyroid hormones play in regulation of renal epidermal growth factor (EGF) production, we characterized the effect of triiodothyronine (T3) administration on renal EGF expression in adult rats. The action of T3 to regulate EGF production was examined under one condition in which renal EGF expression is known to be diminished, posthypophysectomy, and in pituitary-intact rats. Levels of mature EGF, EGF precursor, and EGF mRNA, reduced in kidneys of hypophysectomized rats compared with pituitary-intact animals, increased significantly following the administration of T3 to hypophysectomized rats. Thus replacement of thyroid hormone alone was sufficient to enhance renal EGF expression. Induction of a hyperthyroid state in normal rats by injection of T3 for 4 days increased levels of extractable immunoreactive mature EGF, EGF precursor present in renal membranes, and EGF mRNA measured in kidneys. Levels of EGF in circulation were undetectable under all experimental conditions. We conclude that T3 enhances the renal synthesis of EGF in both hypopituitary and pituitary-intact rats. Enhancement of renal EGF expression is one mechanism that must be considered to explain the actions of thyroid hormones on kidney.

Topics: Animals; Blotting, Western; Body Weight; Cell Membrane; Electrophoresis, Polyacrylamide Gel; Epidermal Growth Factor; Gene Expression; Hypophysectomy; Kidney; Male; Rats; Rats, Sprague-Dawley; Reference Values; RNA, Messenger; Submandibular Gland; Triiodothyronine

Heparin binding epidermal growth factor (HB-EGF), a new member of the EGF family, is a potent mitogen for smooth muscle cells, fibroblasts, and mesangial cells. To study whether the HB-EGF is involved in the development of diabetic nephropathy, we measured the expression of the HB-EGF gene in the kidney tissues of streptozotocin-induced diabetic rats by Northern blot analysis. The mean kidney weight of diabetic rats without strict blood sugar control was significantly increased as compared to that of the control group. Renal HB-EGF mRNA expression was also increased in diabetic rats without strict blood sugar control at 7 days after induction of diabetes and remained elevated for the entire 3-month study period. Strict insulin treatment abolished the elevation of HB-EGF mRNA expression and kidney growth. As HB-EGF is a mitogen for mesangial cells, our results suggest that HB-EGF may be involved in the development of diabetic nephropathy.

Topics: Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; Epidermal Growth Factor; Gene Expression; Heparin; Heparin-binding EGF-like Growth Factor; Insulin; Intercellular Signaling Peptides and Proteins; Kidney; Male; Rats; Rats, Wistar; Reference Values; RNA, Messenger; Transcription, Genetic

Calorie restriction reduces mammary mitogenesis and tumorigenesis. To test whether epidermal growth factor (EGF) levels are influenced by calorie intake, 72 four-week-old C3H/HeOu mice were separated into two groups and either fed ad libitum (group AL) or calorie-restricted at a mean 19% (group CR). Three mice from each group were evaluated when 6, 8, 10, and 12 weeks old for submandibular gland transcription of EGF and beta-actin RNA for levels of EGF protein in the submandibular gland, mammary gland, and serum and for immunohistological evidence of EGF protein within the submandibular and mammary glands. Submandibular levels of EGF RNA and protein and mammary and serum levels of EGF protein were similar between dietary groups when mice were 6 and 8 weeks old. Mean EGF:beta-actin RNA transcription in submandibular glands of 12-week-old mice were approximately 10-fold greater in AL compared to CR mice (ratio means, 1.499 versus 0.157, respectively; P < 0.01). Mean submandibular levels of EGF protein were greater in 10-week-old AL compared to CR mice (7017.4 versus 4098.5 ng/mg protein, respectively; P < 0.05) and even greater in 12-week-old AL compared to CR mice (4342.6 versus 137.9 ng/mg protein; P < 0.001). Mean mammary levels of EGF protein were greater among 12-week-old AL compared to CR mice (7.8 versus 5.0 ng/mg protein; P < 0.05). Serum levels of EGF did not differ between dietary cohorts. More anti-EGF immunoprecipitate was present in submandibular and mammary gland sections of 10- and 12-week-old AL compared to CR mice. Lowered EGF levels may contribute to the antiproliferative and antineoplastic effects of calorie restriction.

Topics: Animals; Base Sequence; Body Weight; Diet, Reducing; Energy Intake; Epidermal Growth Factor; Female; Mammary Glands, Animal; Mice; Mice, Inbred C3H; Molecular Sequence Data; RNA, Messenger; Submandibular Gland

In this study we tested the effects of repeated administrations of Epidermal Growth Factor (EGF) and Transforming Growth Factor-alpha (TGF-alpha) on mouse pups' neurobehavioral development. Each subject was injected subcutaneously with either EGF or TGF-alpha on postnatal days 2, 4, 6, 8, and 10. Pups treated with these two peptides showed accelerated eyelid opening and eruption of the lower incisors when compared to Cytochrome c-injected control littermates. EGF, but not TGF-alpha, resulted in a slight body growth retardation. When scored for a number of neurobehavioral parameters, EGF pups showed a delayed appearance of the righting reflex. Also, EGF-treated pups exhibited greater ultrasonic vocalization calling rates than controls when tested on postnatal day 7. Overall, TGF-alpha administration resulted in minor effects, when compared with EGF treatment, probably as a result of the lower dose administered (EGF: 3.5 mg/kg vs TGF-alpha: 1 mg/kg). TGF-alpha affected pups' eyelid opening and incisor eruption, similarly to EGF, but seemed to exert an opposite effect on some neurobehavioral scores, in line with what was already reported for Nerve Growth Factor (NGF) (Calamandrei and Alleva, 1989). These results confirm the role played by polypeptide growth factors on mammalian physical and neurobehavioral development and suggest that TGF-alpha might affect mouse brain development in a similar fashion as NGF.

Topics: Animals; Behavior, Animal; Body Weight; Cytochrome c Group; Developmental Biology; Epidermal Growth Factor; Mice; Neurons; Transforming Growth Factor alpha

Effects of sequential use of epidermal growth factor followed by interferon gamma on healing response after severe oesophageal corrosive burns has been demonstrated. This sequential treatment improves the inflammatory response of the initial phase and prevents residual stenosis. The aim of this study was to evaluate the use of interferon gamma alone in the same condition.. The study was performed in 5 groups (n = 15) of Wistar rats: control, placebo, epidermal growth factor alone, interferon gamma alone and epidermal growth factor for 5 days followed by interferon gamma from the 6th to 20th day. The last 4 groups had an oesophageal injury caused by a solution of 2.5 N NaOH. The efficacy of treatment was assessed on days 2, 5 and 20 on: weight gain, oesophageal internal lumen, stenosis index: wall thickness/lumen diameter, collagen production.. Interferon gamma significantly reduced residual stenosis frequency while it did not improves the initial healing process. A complete effect on the two healing phases was only observed in animals having the sequential treatment.. These results could lead to clinical trial in man to evaluate efficacy of sequential treatment with epidermal growth factor-interferon gamma in oesophageal corrosive burns.

Topics: Animals; Body Weight; Burns, Chemical; Caustics; Drug Therapy, Combination; Epidermal Growth Factor; Esophageal Stenosis; Hydroxyproline; Interferon-gamma; Male; Rats; Rats, Wistar

The effect of oral epidermal growth factor (EGF) on histological and biochemical changes in epithelium in the small intestine was studied in colostrum-deprived neonatal pigs. Forty-eight pigs were infected at 4 days of age with 2 x 10(7) plaque-forming units of porcine group A rotavirus and orally fed a simulated sow-milk diet supplemented with 0.0, 0.5, or 1.0 mg/L recombinant human EGF. Sixteen noninfected pigs were fed a diet without EGF supplementation. Infected pigs developed severe diarrhea; they also consumed 25% less food and gained 60% less weight than noninfected pigs. Pigs were killed 8 days postinfection to collect samples at seven equidistant points in the small intestine. Rotavirus infection decreased villus height by 37% and reduced specific activity of lactase by 54%, of leucine aminopeptidase by 43%, and of alkaline phosphatase by 54% in the small intestine, compared with noninfected pigs. Only the supraphysiological dose of EGF (1.0 mg/L) consistently increased villus height in the proximal and mid-small intestine and lactase-specific activity in the mid-small intestine of rotavirus-infected pigs. However, this dose was only partially effective in restoring intestinal mucosal dimensions and enzyme activities. Supplemental EGF did not hasten the resolution of diarrhea. These data indicate that high physiological levels of EGF are beneficial in stimulating recovery of epithelium in the small intestine following rotavirus infection.

Topics: Administration, Oral; Animals; Animals, Newborn; Body Weight; Diarrhea; Disease Models, Animal; Epidermal Growth Factor; Food, Fortified; Intestinal Mucosa; Intestine, Small; Rotavirus Infections; Swine

Nude mice bearing xenografts of the gastrin-responsive human gastric carcinoma MKN45 cell line were treated for 4 to 5 weeks with bombesin/gastrin-releasing-peptide(GRP) antagonist (RC-3095), somatostatin analogues RC-160 and SMS 201-995, or the combination of RC-3095 and RC-160. Tumor volumes and weights were reduced significantly to a similar extent by RC-160 and SMS 201-995, administered by daily s.c. injections at a dose of 100 micrograms/day. Bombesin/GRP antagonist RC-3095, given s.c. at a dose of 20 micrograms/day, had the greatest inhibitory effect on tumor growth. The combination of RC-3095 with RC-160 did not further potentiate the suppression of tumor growth. Histologically, the number of mitotic cels decreased significantly in the groups treated with RC-160 or the combination of RC-3095 with RC-160. Serum gastrin levels were significantly diminished in all treated groups. Therapy with RC-160 or the combination also significantly decreased levels of serum growth hormone. Receptor assays on tumor membranes showed that bombesin was bound to 2 classes of receptor sites, one with high affinity and low capacity, the other with low affinity and high capacity. Binding sites for epidermal growth factor (EGF) were down-regulated in tumor cells after treatment with RC-3095, RC-160 or the combination of RC-3095 with RC-160. In studies in vitro, both RC-160 and RC-3095 significantly inhibited the proliferation of MKN45 cells in culture as measured by cell number. These data demonstrate, for the first time, that the growth of human gastric cancer in nude mice can be inhibited not only by somatostatin analogues, but also by administration of modern bombesin/GRP antagonists, such as RC-3095.

Topics: Adenocarcinoma; Amino Acid Sequence; Animals; Antineoplastic Agents; Binding Sites; Body Weight; Bombesin; Cell Division; Epidermal Growth Factor; Female; Humans; Insulin-Like Growth Factor I; Male; Mice; Mice, Nude; Middle Aged; Molecular Sequence Data; Neoplasm Transplantation; Octreotide; Peptide Fragments; Somatostatin; Stomach Neoplasms; Transplantation, Heterologous; Tumor Cells, Cultured

The effect of sialoadenectomy (Sx) and epidermal growth factor (EGF) administration on testicular function was investigated in 8-week old C3H mice. Animals were divided initially into three groups: sham operated controls, Sx, and Sx + EGF treated (100 micrograms./kg./day subcutaneously for 28 days). Sialoadenectomy completely depleted the circulating levels of EGF and reduced body weight and reproductive organ weights. However, kidney weight was not affected. Quantitative analysis of spermatogenesis showed a decrease in preleptotene and pachytene spermatocytes and round spermatids, which resulted in a decrease in sperm counts. Sperm motility and fertility were also significantly decreased. Endocrinologic studies showed a 2- and 6-fold elevation in intratesticular and serum levels of testosterone and a decrease in luteinizing hormone (LH) levels. Follicle stimulating hormone levels were not altered. Administration of EGF to the Sx animals maintained reproductive organ weights, spermatogenesis and levels of LH and testosterone closer to control values; however, sperm motility was not maintained at control value. That sialoadenectomy resulted in a decline in androgen-dependent parameters, in spite of an elevation in testosterone levels, and EGF maintained them closer to the control value suggested that EGF may modulate androgen action. A comparison was therefore carried out between the effects of Sx and administration of flutamide (F), an androgen receptor blocker. Animals were subjected to Sx, F treatment (100 mg./kg./day subcutaneously for 28 days), Sx + F, or Sx + F + EGF. The effects of Sx and F treatment on organ weights, sperm counts and sperm motility were more or less similar. As expected, flutamide treatment increased LH and FSH levels, and testosterone levels were normal. The Sx + F animals showed no further decrease in organ weights, sperm count and motility. Treatment with Sx + F increased intratesticular and serum levels of testosterone by 2- and 10-fold. Circulating levels of LH and FSH were the same as in the flutamide-treated group. Administration of EGF to Sx + F maintained all these parameters, except sperm motility, closer to the control value. These results suggest that EGF either bypasses flutamide effects and acts directly or that EGF modulates androgen action at one or more steps in the signal transduction pathway in the male reproductive organs.

Topics: Animals; Body Weight; Epidermal Growth Factor; Flutamide; Follicle Stimulating Hormone; Luteinizing Hormone; Male; Mice; Mice, Inbred C3H; Organ Size; Salivary Glands; Sexual Maturation; Sperm Count; Sperm Motility; Spermatogenesis; Testis; Testosterone

1. Epidermal growth factor (EGF) has recently been shown to stimulate both polydipsia and polyuria and the aim of this study was to determine which was the primary response. Ewes received a continuous intravenous saline infusion (100 ml day-1) for 12 days (days 1-12) and EGF at doses of 0 (n = 6) or 10 micrograms h-1 (n = 6) over days 5-8. The supply of water was ad libitum during days 1-4 and 9-12, but was fixed at the pretreatment mean of days 1-4 for each ewe during days 5-8. 2. During the period of fixed water intake, the EGF-treated ewes experienced mild dehydration with elevated plasma osmolality, sodium, renin and arginine vasopressin (AVP) concentrations and slightly reduced plasma atrial natriuretic peptide (ANP) concentrations. 3. When the supply of water returned to ad libitum, the EGF-treated ewes increased their water intake by 105% (5.25 +/- 0.28 vs. 2.55 +/- 0.19 l day-1) and subsequently fluid balance was restored; plasma electrolyte and hormone responses also returned to normal. 4. This experiment demonstrates that EGF infused at a dose rate of 10 micrograms h-1 I.V. into sheep has a direct renal diuretic effect.

Topics: Animals; Appetite; Body Weight; Diuresis; Electrolytes; Epidermal Growth Factor; Female; Hematocrit; Hormones; Infusions, Intravenous; Kidney; Potassium; Sheep; Sodium; Water-Electrolyte Balance

Experimental diabetes was induced in rats with streptozocin before mating, and the influence of diabetes on epidermal growth factor (EGF) in milk and on other milk components was studied. Throughout the lactation period, a significant decrease was found both in the production of milk and in the concentration of EGF in milk from untreated diabetic rats compared with an insulin-treated diabetic group and a control group. Thus, the total output of EGF in milk from diabetic rats was considerably decreased. The concentrations of total protein and haptocorrin, a cobalamin (vitamin B12)-binding protein, and the content of fat, however, were unaltered by diabetes. Therefore, the decrease in milk EGF seemed to be selective compared with total protein in milk. The pups of diabetic dams had reduced body weights within 1 wk of lactation and reduced body lengths on d 16 of lactation compared with control pups. Furthermore, the time of eyelid opening was delayed, but no difference in the time of tooth eruption was observed. Insulin-treatment of diabetic rats restored the milk volume and the EGF concentration to values comparable to those of the controls. Pups of the insulin-treated diabetic dams were comparable to the pups of the controls. These results indicate that insulin deficiency in lactating rats causes a decrease in the lactational performance and in the EGF content of milk.

Topics: Animals; Body Weight; Diabetes Mellitus, Experimental; Epidermal Growth Factor; Female; Growth; Insulin; Lactation; Lipid Metabolism; Litter Size; Milk; Milk Proteins; Pregnancy; Pregnancy in Diabetics; Rats; Rats, Wistar; Transcobalamins

Effects on bone remodeling have been attributed to epidermal growth factor (EGF). Sialoadenectomy (SX) removes the major source of EGF in rodents and decreases both salivary and serum EGF levels. EGF effects on rat alveolar bone remodeling manifested by molar drift (MD) and orthodontic tooth movement (OTM) were examined using the following two approaches: 1) EGF depletion by SX and replacement by orally administered EGF (50 micrograms.animal-1.day-1); 2) sham rats supplemented with matching amounts of EGF. MD and OTM were measured using cephalometric radiographs; bone formation was measured histomorphometrically using tetracycline labeling. Normal MD was not detected after SX, and alveolar bone formation was significantly reduced both around the tooth and in nondental sites. Replacement EGF given to SX rats and supplemental EGF administered to sham rats changed the direction and enhanced the rate of MD. A mesially directed orthodontic force applied to the molars of SX animals increased bone formation on the distal aspect of the tooth roots. Supplemental EGF did not significantly affect OTM. EGF affects alveolar bone remodeling, as manifested clinically by alterations in normal maxillary MD.

Topics: Administration, Oral; Analysis of Variance; Animals; Blotting, Western; Body Weight; Bone Development; Epidermal Growth Factor; Male; Maxilla; Molar; Rats; Rats, Sprague-Dawley; Reference Values; Saliva; Submandibular Gland; Time Factors; Tooth Movement Techniques

The effects of epidermal growth factor on intestinal glucose transport were examined in mice. Glucose transport measurements were performed using an in vitro assay system that estimated the rate of accumulation of [3H]3-O-methyl-D-glucose. In Experiment 1, two-mo-old male and female mice were subcutaneously injected once daily with 0, 150 or 300 micrograms epidermal growth factor/kg body weight for 3 d. Jejunal glucose active transport was increased in a dose-dependent manner. There were no gender-related differences in intestinal glucose transport or the response to exogenous epidermal growth factor. In Experiment 2, 2-, 10- and 18-mo-old mice were administered 0 or 300 micrograms epidermal growth factor/kg body weight using a treatment similar to that used in Experiment 1. Active intestinal glucose transport was 30% greater in response to epidermal growth factor in each of the three age groups. Ouabain-sensitive and -insensitive jejunal oxygen consumption was increased in response to epidermal growth factor such that total jejunal respiration was stimulated 15 to 31%. The epidermal growth factor related percentage increase in glucose absorption was similar to the percentage increase in oxygen consumption such that the apparent energetic efficiency of glucose transport was unaffected. In both experiments, the active component of glucose transport was increased by epidermal growth factor while passive transport was not affected. Jejunal morphology and mucosal DNA and protein concentration were not altered by epidermal growth factor treatment. Epidermal growth factor-induced increases in intestinal absorption was not attributable to mucosal hyperplasia.

Topics: Age Factors; Animals; Biological Transport, Active; Body Weight; Dose-Response Relationship, Drug; Eating; Epidermal Growth Factor; Female; Glucose; Injections, Subcutaneous; Intestinal Absorption; Jejunum; Male; Mice; Mice, Inbred ICR; Organ Size; Oxygen Consumption; Random Allocation; Sex Characteristics

Several growth factors have been demonstrated to be involved in fetal growth. In this study, physiological significance of two growth factors, epidermal growth factor (EGF) and insulin-like growth factor-I (IGF-I) on fetal growth was evaluated. IGF-I stimulated 3H-glycine uptake by cultured trophoblast cells from term pregnancy while EGF did not stimulate it. A large part of IGF-I was associated with its binding proteins (IGFBPs) in the circulation and one of IGFBPs, IGFBP-1 inhibited 3H-glycine uptake by IGF-I in a dose dependent manner. IGF-I also stimulated 3H-aminoisobutyric acid (3H-AIB) release by trophoblast cells when cells were saturated with 3H-AIB first, then stimulated with IGF-I. In animal experiments, placental weight but not fetal weight was suppressed when EGF antiserum was administrated to maternal mice, however, fetal lung maturity in terms of lamella body produced in type II alveolar cells was suppressed in antiserum given group. When anti IGF-I antiserum was administrated to pregnant mice, both fetal and placental weight were significantly suppressed and transfer of 3H-AIB to fetus was also suppressed. In contrast, antiserum to IGFBP-1 stimulated fetal growth and transfer of 3H-AIB to fetus. Furthermore, fetal lung on Day 17 in anti IGFBP-1 antiserum administrated mice showed morphologically advanced changes that were equivalent to Day 18 or 19 of control. These results indicate that EGF and IGF-I regulate fetal growth and maturation independently and that IGF-I and IGFBP-1 influence fetal development in a counter regulatory system.

Topics: Amino Acids; Animals; Biological Transport; Body Weight; Carrier Proteins; Dose-Response Relationship, Drug; Embryonic and Fetal Development; Epidermal Growth Factor; Female; Fetal Organ Maturity; Gestational Age; Insulin-Like Growth Factor Binding Protein 1; Insulin-Like Growth Factor I; Lung; Maternal-Fetal Exchange; Mice; Molecular Weight; Organ Size; Placenta; Placentation; Pregnancy; Random Allocation; Trophoblasts

Ovariectomy (Ovx) of mice significantly increases the epidermal growth factor (EGF) concentration in the submandibular gland. To elucidate the role of this elevated EGF in obesity of Ovx mice, we examined the effects of sialoadenectomy (Sx) and anti-EGF rabbit antiserum administration on the body weight (BW) gain and carcass fat deposition in Ovx animals. Studies were performed in four groups of mice consisting of control, Ovx, Ovx+Sx, and Ovx+anti-EGF groups. Ovx increased the BW gain compared with the control animals, whereas Sx and anti-EGF significantly reduced it. Although the relative weights (weight ratio to BW) of the liver and kidney were not significantly changed by Ovx, Sx, or anti-EGF treatment of Ovx mice, the relative weights of mesenteric, parametrial, and subcutaneous fat tissues were increased in Ovx mice, and this increase was significantly reduced by Sx or anti-EGF administration. Ovx induced adipocyte hypertrophy, and this effect was eliminated by Sx and anti-EGF. Moreover, acyl-CoA synthetase mRNA level was increased by Ovx, and this increase was reduced by Sx and anti-EGF in mesenteric fat tissue. These findings suggest that elevation of EGF may play a role in the induction of obesity in Ovx mice.

Topics: Acetate-CoA Ligase; Adipose Tissue; Animals; Body Weight; Eating; Epidermal Growth Factor; Female; Kidney; Lipids; Liver; Mice; Mice, Inbred C3H; Obesity; Organ Size; Ovariectomy; RNA, Messenger; Submandibular Gland

Pancreatic cancer cell lines overexpress epidermal growth factor (EGF) receptors and also have the capacity to produce transforming growth factor alpha (TGF alpha), the alternate agonist of the EGF receptor. The purpose of this study was to determine if TGF alpha had a trophic effect on the growth of pancreatic cancer in vivo. Syrian golden hamsters were inoculated with 50,000 H2T hamster ductal pancreatic cancer cells. The hamsters were then randomised to three equal groups: the groups received either saline (control), EGF, or TGF alpha, each by intraperitoneal injection, three times a day. Treatment continued for seven weeks, and each week the hamsters were weighed and tumour areas were measured. The hamsters were then killed, and the tumours were excised, weighed, and extracted for assay of DNA content as a measure of cellularity. From week four onwards both EGF and TGF alpha significantly stimulated tumour growth. Although tumour weights were not significantly different, tumour DNA content had nearly doubled after exposure to both EGF and TGF alpha. It is concluded that like EGF, TGF alpha can stimulate pancreatic cancer growth in vivo, and this may in part explain the aggressive nature of these cancers in clinical practice.

Topics: Animals; Body Weight; Cricetinae; DNA, Neoplasm; Epidermal Growth Factor; Injections, Intraperitoneal; Mesocricetus; Pancreatic Neoplasms; Random Allocation; Transforming Growth Factor alpha; Tumor Cells, Cultured

The systemic effects of epidermal growth factor (EGF) ointment containing nafamostat (NM), gabexate, or gelatin was studied in rats with burns or open wounds. At 1 d after burn, plasma epinephrine, cortisol, and glutamic-oxalacetic transaminase (GOT) levels were elevated, but treatment with EGF plus NM (EGF+NM) ointment significantly suppressed the increase in these levels. Further, there was no loss of body weight in the open wound model following treatment with EGF+NM ointment, while loss of body weight occurred in animals in which EGF ointments without NM were applied. Increases in plasma epinephrine 1 d after open wound formation were also suppressed by the application of EGF+NM ointment. Treatment with EGF ointment containing gabexate (GX) or gelatin (GL) ameliorated changes in body weight that occurred after open wound formation, while loss of body weight in animals with open wounds occurred following the application of ointment base, EGF ointment, GX ointment, or GL ointment. The present study thus indicates that the topical application of EGF ointment containing a protease inhibitor has ameliorative systemic effects.

Topics: Animals; Aspartate Aminotransferases; Benzamidines; Body Weight; Burns; Drug Interactions; Drug Synergism; Epidermal Growth Factor; Epinephrine; Gabexate; Gelatin; Guanidines; Hydrocortisone; Male; Ointments; Protease Inhibitors; Rats; Rats, Wistar; Wounds and Injuries

Female Syrian golden hamsters with N-nitroso-bis (2-oxopropyl) amine (BOP)-induced pancreatic cancers were treated for 2 months with bombesin/gastrin-releasing peptide (GRP) antagonist D-Tpi6,Leu13 psi(CH2NH)Leu14 bombesin(6-14) (RC-3095). Bombesin and GRP(14-27) were also administered alone and in combination with the antagonist RC-3095. RC-3095 exerted a dose-dependent inhibitory effect on growth of pancreatic cancers. The number of animals with pancreatic cancers was significantly lower in the group treated with 60 micrograms/day of RC-3095 and the weight of tumorous pancreata was reduced. Administration of bombesin or GRP alone did not stimulate the growth of pancreatic tumors and, in fact, had a slightly suppressive effect on cancers which was significant only in Experiment I. Bombesin and GRP (14-27) given together with RC-3095 did not nullify the inhibitory effect of the antagonist on pancreatic cancer growth. Actually, a greater inhibition of pancreatic tumors was observed after administration of RC-3095 together with bombesin or GRP, than with RC-3095 alone. The mechanism of action of bombesin, GRP, and bombesin antagonists on pancreatic cancers appears to be complex. The inhibitory effect of bombesin antagonists on pancreatic cancer growth was accompanied by a decrease in the binding capacity of EGF receptors in tumor membranes. Administration of bombesin also caused a down-regulation of EGF receptors and the greatest decrease in binding capacity of EGF receptors was observed after treatment with RC-3095 in combination with GRP. Inhibition of pancreatic cancer can thus be tentatively explained by some common pathways in the action of bombesin, GRP and their antagonists, that could be mediated by interference with EGF-receptor mechanisms.

Topics: Animals; Body Weight; Bombesin; Carcinoma; Cricetinae; Dose-Response Relationship, Drug; Down-Regulation; Epidermal Growth Factor; ErbB Receptors; Female; Gastrin-Releasing Peptide; Gastrins; Growth Hormone; Insulin-Like Growth Factor I; Mesocricetus; Nitrosamines; Pancreatic Neoplasms; Peptide Fragments; Peptides; Receptors, Bombesin; Receptors, Neurotransmitter

Epidermal growth factor (EGF) in mouse submandibular gland (SMG) is synthesized in the granular convoluted tubular (GCT) cells. The synthesis of EGF in SMG has been shown to be increased by thyroid hormone. This increase was attributed to the increase in EGF mRNA. Not known is how thyroid hormone increases the mRNA level. In the present study the effect of thyroid hormone administration on EGF gene expression in SMG was studied in hypothyroid mice. Hypothyroidism was induced by treating the mice with propylthiouracil. The amount of SMG EGF mRNA was markedly decreased in hypothyroid mice. Administration of T3 increased the mRNA in a dose-dependent manner. The increase in EGF mRNA by T3 was evident as early as 6 h after T3 administration. A nuclear run-off assay indicated that the induction of EGF gene expression by T3 is at a transcriptional level. Bromodeoxyuridine incorporation into GCT cells was not affected by T3 administration, suggesting that T3 does not cause the proliferation of these cells. In situ hybridization revealed that T3 increases EGF mRNA in GCT cells at a single cell level. These results suggest that thyroid hormone increases EGF gene transcription without affecting cellular proliferation.

Topics: Animals; Body Weight; Bromodeoxyuridine; Epidermal Growth Factor; Gene Expression; Hypothyroidism; In Situ Hybridization; Male; Mice; Organ Size; Propylthiouracil; RNA, Messenger; Submandibular Gland; Thyroxine; Transcription, Genetic; Triiodothyronine

Time- and dose-dependent alterations in epidermal growth factor receptor (EGF-R) ligand binding and protein kinase activity were observed in hepatic plasma membranes of TCDD-treated rainbow trout. Trout were dosed by a single ip injection of TCDD in a corn oil vehicle. A single ip injection of TCDD (10 micrograms TCDD/kg body wt) caused a maximal reduction of EGF binding to hepatic plasma membranes by 10 days post-treatment and remained reduced until Day 40. EROD activity in the liver microsomes of TCDD-treated trout increased relative to that in untreated fish over the course of the study. Protein kinase C and tyrosine kinase activity as well as EGF-receptor phosphorylation was greater in livers of treated fish than in those of control fish within 5 days but returned to control levels by 40 days postinjection. In a dose-response study, EGF binding was reduced in a dose-dependent manner with an ED50 of 0.17 micrograms TCDD/kg wet wt while EROD activity was induced with an ED50 of 0.79 micrograms TCDD/kg. The reduction in EGF binding was correlated to an increase in EROD activity, protein kinase C activity, and tyrosine kinase activity but was negatively correlated to EGF-receptor phosphorylation. Of the parameters examined in both the time-course and dose studies, protein kinase C was the best predictor of the reduction of EGF binding to hepatic plasma membranes of rainbow trout. The results from this study are consistent with the hypothesis that the mode of action of TCDD on the EGF receptor is in part mediated through the protein kinase C activity. It also suggests that the toxic mode of action of TCDD is similar in rainbow trout and mammals.

Topics: Animals; Binding Sites; Body Weight; Cell Membrane; Cytochrome P-450 CYP1A1; Cytochrome P-450 Enzyme System; DDT; Dieldrin; Dose-Response Relationship, Drug; Epidermal Growth Factor; ErbB Receptors; Liver; Organ Size; Oxidoreductases; Phosphorylation; Polychlorinated Dibenzodioxins; Protein Kinase C; Protein-Tyrosine Kinases; Radioligand Assay; Trout

Epidermal growth factor (EGF) is a potent inhibitor of adipose differentiation in vitro and delays adipose tissue development in vivo. Here we show that in the homozygous male obese mice the level of EGF in the submaxillary gland and plasma is significantly lower than in the glands and plasma of age-matched control littermates. This EGF deficiency in ob/ob mice was observed as early as 5 wk of age when obesity had just become apparent and was also found in adult mice. The level of prepro-EGF mRNA expression in the submaxillary gland was also lower in obese mice than in control littermates. However, the level of kidney prepro-EGF mRNA was the same in mice with both phenotypes, suggesting that the regulation of prepro-EGF mRNA expression is different in both tissues. These results indicate that genetic obesity in mice is accompanied by a decrease in the production of EGF.

Topics: Adipose Tissue; Animals; Body Weight; Epidermal Growth Factor; Female; Kidney; Male; Mice; Mice, Inbred C57BL; Mice, Obese; Obesity; Organ Size; Protein Precursors; RNA, Messenger; Submandibular Gland

Acute and late effects of neonatal estrogen treatment were studied in NMRI mice treated with diethylstilbestrol (DES) or estradiol-17 beta (E2) on days 1 to 5 after birth (estrogenized females). The uterine wet weight (UWW) response in 6-day-old females, after 5 daily treatments with DES, had a peak at a daily dose of 10(-2) micrograms DES and declined with higher doses. Females (26-day-old) treated with DES or E2 neonatally had a reduced UWW response to a challenge with DES; on a dose basis, DES was more effective neonatally than E2. A single injection with DES or E2 in the neonatal period stimulated mitotic activity in the uterine horn epithelium; the UWW response to a 24-h DES pulse increased from day 2 to 6 after birth, but the uterine epithelial mitotic rate response decreased. Epidermal growth factor (EGF) was a more potent stimulator of mitotic activity than DES or E2. DES inhibited mitotic activity in the uterine cervical epithelium; EGF protected from this DES effect. In adult estrogenized females, EGF-induced uterine stimulation of 3H-thymidine incorporation subsided more rapidly than in control females; uterine epithelium did not respond to EGF in vitro. Uterine stroma of adult estrogenized females is postulated to house a population of cells under nonovarian proliferation control while the uterine epithelium may be under influence of an ovary-dependent proliferation inhibiting factor that is gradually lost under culture conditions.

Topics: Animals; Animals, Newborn; Body Weight; Diethylstilbestrol; DNA; Epidermal Growth Factor; Estradiol; Estrogens; Female; Male; Mice; Mitosis; Ovariectomy; Progesterone; Thymidine; Uterus

The effects of testosterone (TP) and thyroxine (T4) on the level of epidermal growth factor (mEGF) in the thyroid were compared in a hypothyroid mouse model. Groups of five adult female BALB/c mice were given a "severe" hypothyroid regimen consisting of an iodine deficient diet together with oral and s.c propylthiouracil (PTU). Sialoadenectomy or sham operation was performed after 18 days on the hypothyroid regimen. The mice convalesced on normal diet for 5 days and beginning from day 23 received either T4, 1 ug/g or 2 ug/g, s.c daily or TP, 0.3 mg or 0.75 mg, i.m. every third day until day 33, while continuing the hypothyroid regimen. Control mice received normal diet and vehicles for the various injections. The mice were killed on day 33 and thyroidal EGF levels determined by radioimmunoassay. The mean+S.E. levels of mEGF in the thyroid were 10.12 +/- 1.75 ng/mg protein (control), 3.82 +/- 0.67 ng/mg (hypothyroid; p < 0.01), 3.07 +/- 1.52 (T4, 1 ug/g; p < 0.02), 2.59 +/- 0.46 ng/mg (T4, 2 ug/g; p < 0.01), 8.58 +/- 2.48 (TP, 0.3 mg), and 9.65 +/- 1.86 (TP, 0.75 mg). Thus thyroidal mEGF levels decreased significantly in all groups except those subsequently treated with testosterone; T4 was ineffective in reversing the tissue depletion of mEGF in this model. These results show that mEGF levels in the thyroid could be depleted by hypothyroidism and may also be androgen responsive.

Topics: Animals; Body Weight; Disease Models, Animal; Dose-Response Relationship, Drug; Epidermal Growth Factor; Female; Hypothyroidism; Mice; Mice, Inbred BALB C; Organ Size; Propylthiouracil; Proteins; Radioimmunoassay; Salivary Glands; Testosterone; Thyroid Gland; Thyroxine

The effects of administering insulin-like growth factor I (IGF-I) were examined in a model of ischemic acute tubular necrosis in rats. Injury was induced by 75 min of bilateral renal artery occlusion. Compared to rats administered vehicle, rats administered IGF-I (100 micrograms/day via continuous subcutaneous infusion) had significantly lower serum creatinine and blood urea nitrogen levels over the course of 7 days postocclusion. Glomerular filtration rate as determined by inulin clearance was examined on day 2 postocclusion and was significantly increased in IGF-I-treated animals (0.16 +/- 0.02 ml per min per 100 g of body weight) compared to vehicle-treated controls (0.08 +/- 0.02 ml per min per 100 g of body weight). The weight loss that occurred during the course of acute tubular necrosis was ameliorated by IGF-I. Mortality was reduced from 36.7% in vehicle-treated rats to 7.1% in rats administered IGF-I. Histologically, there was much less renal injury evident at day 7 postocclusion in the IGF-I-treated rats compared to vehicle-treated controls. In contrast, growth hormone (200 micrograms administered subcutaneously for 4 days) did not affect recovery of renal function or reduce mortality postreperfusion. This report demonstrates a beneficial effect of IGF-I administration in the setting of acute tubular necrosis. Several properties of IGF-I render it a pharmacological agent with excellent potential for treatment of this condition in humans.

Topics: Animals; Body Weight; Epidermal Growth Factor; Growth Hormone; Insulin-Like Growth Factor I; Kidney; Kidney Tubular Necrosis, Acute; Male; Rats; Rats, Sprague-Dawley

The mouse thyroid gland contains significant concentrations of immunoreactive epidermal growth factor (EGF). To determine whether thyroidal EGF represents material obtained from the SMG via the circulation, we have compared EGF concentrations in sialoadenectomized (Sx) and sham-operated (Sh) BALB/c mice 30 days after surgical removal of the SMG. We found that the thyroids of Sx male and female mice had a significant increase in EGF concentration. The mean thyroidal EGF concentration (ng/mg wet weight) was 3.67 +/- 0.58 for Sx males, 1.53 +/- 0.47 for Sh males (p less than 0.02), 3.03 +/- 0.64 for Sx females, and 1.08 +/- 0.54 for Sh females (p less than 0.001), respectively. Thus EGF found in the mouse thyroid gland does not appear to arise from the SMG, and the thyroid appears to be an independent source of EGF synthesis.

Topics: Animals; Body Weight; Epidermal Growth Factor; Female; Male; Mice; Mice, Inbred BALB C; Organ Size; Radioimmunoassay; Salivary Glands; Thyroid Gland

Epidermal growth factor (EGF) is trophic for varying regions of the developing gastrointestinal tract (GIT) of suckling rats. The presence of large amounts of EGF in milk from various species, combined with low production of EGF by suckling animals, led to speculation that milk is a major source of EGF for suckling rats. We report that short-term fasting (8 hr) of 12-day-old suckling rats resulted in a significant decrease in the levels of immunoreactive EGF (irEGF) in the GIT. Pups refed by lactating mothers for 1 to 4 hr exhibited an increase in irEGF to original levels, whereas pups fed a rat milk substitute by gastric gavage did not have an increase in irEGF content. The irEGF levels in the GIT of pups that were manually fed normal rat milk, or rat milk substitute supplemented with EGF, returned to the prefasted levels. Fasted suckling rats refed 2 ml of rat milk in 2 h exhibited significantly higher level of irEGF in the GIT than did those refed with 0.5 ml in 45 min. Since rat milk irEGF exists in three distinct forms (A, B, and C; C is equal to authentic submandibular gland EGF, the irEGF forms in the GIT were characterized by native polyacrylamide gel electrophoresis. In the stomach luminal contents of the fed suckling rats, only the larger form, Peak B, was observed. Both the luminal content and the mucosa scrapings of all other segments of all groups contained only Form D (comigrating with desarginyl EGF), a metabolic derivative of EGF. All forms were immunoreactive, exhibited receptor binding, and stimulated DNA synthesis in growth-arrested fibroblasts. The rapid changes in EGF within the GIT of suckling rats suggest the EGF can acutely modify some GIT functions of suckling rats.

Topics: Animals; Animals, Suckling; Body Weight; Digestive System Physiological Phenomena; Duodenum; Eating; Epidermal Growth Factor; Fasting; Female; Intestinal Mucosa; Milk; Muscle, Smooth; Radioimmunoassay; Rats; Rats, Inbred Strains; Stomach

The effects of epidermal growth factor (EGF) on postnatal development of intestinal transport and the physical composition of the microvillus membrane were examined. New Zealand White rabbits received EGF (40 micrograms/kg/d) from d 3 of life to d 17 either intraperitoneally or orogastrically. Intestinal H2O, Na+, and glucose absorption expressed per cm of intestine were significantly increased in animals receiving EGF by either route. When EGF was given by the orogastric route, nutrient absorption rates normalized to mucosal DNA were not elevated; thus, increased absorption induced by orogastric EGF appeared to be secondary to mucosal hyperplasia. In contrast, systemic EGF up-regulated cellular nutrient transport. To evaluate at which membrane level these changes occurred, brush border membrane vesicles were isolated from both the jejunum and ileum of control and EGF-treated animals. Rates of Na(+)-dependent glucose transport into the vesicles revealed that in the ileum systemic EGF up-regulated maximal rates of glucose transport by 54% without affecting the Km. These observations were associated with alterations in the lipid composition and physical properties of the microvillus membrane. EGF-treated animals had significant reductions in membrane cholesterol content and altered ratios of phospholipid subclasses. The net result of these variations was that the microvillus membrane isolated from EGF-treated animals was significantly more fluid than membrane from controls. Thus, these results suggest that EGF modulates development of transport function during the postnatal period both by stimulating mucosal growth and by inducing specific transport processes. Furthermore, these changes are associated with alterations in the physical composition of the microvillus membrane.

Topics: Animals; Animals, Suckling; Body Weight; Cell Membrane; Epidermal Growth Factor; Gastrointestinal Transit; Glucose; Injections, Intraperitoneal; Intestinal Mucosa; Kinetics; Microvilli; Rabbits; Sodium-Potassium-Exchanging ATPase

We studied the effects of hormonal manipulation by orchiectomy, alone or in combination with the aromatase inhibitor aminoglutethimide (AGT), and by luteinizing hormone-releasing hormone agonist (LH-RH-A) (goserelin) treatment on the development of early putative (pre)neoplastic lesions induced in the pancreas of rats and hamsters by azaserine and N-nitrosobis(2-oxopropyl)amine respectively. Treatment of the animals started 1 week after the last injection with carcinogen and continued for 4 months. Orchiectomy caused a significant inhibition of growth of acidophilic atypical acinar cell nodules in the rat model, whereas surgical castration did not show an effect in the hamster model. In rats, but not in hamsters, orchiectomy resulted in a significant decrease in body weight and in absolute, but not relative pancreatic weight. Treatment of the animals with AGT or goserelin did not cause a significant effect on the development of either putative preneoplastic acinar lesions in rat pancreas or early ductular lesions in hamster pancreas. Hamsters showed clearly higher plasma epidermal growth factor (EGF) and insulin-like growth factor 1 (IGF-1) concentrations than rats, while plasma testosterone levels were significantly lower. Plasma EGF and IGF-1 levels decreased with increasing age in both control and treatment groups. Compared to controls there were no clear unequivocal effects of treatment on EGF, IGF-1 and gastrin levels. Plasma testosterone levels decreased by orchiectomy and LH-RH-A treatment. In rats hormone-induced effects on food intake and altered nutritional status might be important with respect to the development of carcinogen-induced preneoplastic pancreatic lesions.

Topics: Aminoglutethimide; Animals; Azaserine; Body Weight; Buserelin; Carcinogens; Cricetinae; Epidermal Growth Factor; Gastrins; Goserelin; Male; Mesocricetus; Nitrosamines; Orchiectomy; Organ Size; Pancreatic Neoplasms; Precancerous Conditions; Rats; Rats, Inbred Strains; Somatomedins; Testosterone

The present study was aimed at assessing whether epidermal growth factor (EGF) and its receptors are present in the gastric mucosa during the healing of gastric ulcers. Immunohistochemical, immunochemical and functional studies were performed in rats after induction of ulcers in the oxyntic mucosa. Controls, which included non-operated and sham-operated animals, displayed only rare cells in the bottom of the oxyntic glands showing EGF-like immunoreactivity. Within one day after ulcer induction, a markedly increased number of chief cells in undamaged mucosa showed intense staining. Concomitantly, there was an increased immunoreactivity for EGF receptors in the mucous neck cells. Maximal immunostaining for both compounds was observed at 3 days after ulcer induction; augmented staining was still demonstrable after 3 weeks. RIA revealed significantly increased EGF concentration in the oxyntic mucosa three days after ulcer induction, and at this stage stimulated gastric acid secretion, measured in a parallel group of chronic fistula rats, indicated significant inhibition. The transient increases in EGF-like and EGF receptor immunoreactivities may stimulate gland cell proliferation. The local release of EGF-like substances may also serve to reduce gastric acidity and thereby promote ulcer healing.

Topics: Animals; Body Weight; Epidermal Growth Factor; ErbB Receptors; Female; Gastric Acid; Gastric Mucosa; Immunohistochemistry; Male; Rats; Rats, Inbred Strains; Stomach Ulcer; Wound Healing

The ability of epidermal growth factor (EGF) to affect adipose tissue development in vivo was investigated. The subcutaneous administration of EGF to newborn NBR rats for 10 days resulted in decreased body weight and fat pad weight that occurred in a dose-dependent fashion. At a dose of 1 micrograms/g of body weight, injected EGF resulted in a 50% decrease of fat pad weight. Although kidney weight was also diminished, the weight of other organs such as liver and intestine remained unchanged or even slightly increased, suggesting that the effect of EGF on fat pad development was not due to a generalized inhibitory action of EGF on the development of the neonate rats. The number of adipocyte precursors in inguinal fat pads of EGF-treated animals was higher than in control animals (1.3-fold for 0.3 micrograms/g of body weight of EGF and 1.8-fold for 1.0 micrograms/g of body weight), whereas the number of mature adipocytes and the amount of triglyceride accumulated per fat pad were concomitantly lower. Adipocyte precursors isolated from EGF-treated animals displayed a reduced differentiation ability in culture and a higher sensitivity to the inhibitory effect of EGF than did cells isolated from control animals. These experiments demonstrate that EGF can retard adipose tissue development in vivo and suggest that EGF plays an important physiological role in the control of adipocyte differentiation.

Topics: Adipose Tissue; Animals; Animals, Newborn; Body Weight; Cell Differentiation; Cell Division; Dose-Response Relationship, Drug; Epidermal Growth Factor; Rats; Triglycerides

Twin-bearing ewes were treated with epidermal growth factor (EGF) to determine its effect on mammogenesis and resultant milk production and composition. The EGF was infused intravenously at a dose rate of 0.5 mg/d in 300 ml saline between days 117 and 139 of gestation; control animals received placebo infusions of saline. All animals then received continuous infusions of 300 ml/d saline on days 139-144. Following parturition 1-5 d later, ewes were milked by hand for 10 d and thereafter were machine-milked until day 16 of lactation. At this level of treatment, EGF was not detected in the circulation during infusion and feed intake was not affected. All ewes gave birth to healthy twin lambs. There were no effects of EGF on birth weights of lambs, live weights of ewes or lengths of gestation. An EGF-immunoreactive material was detected in the mammary secretions of control ewes at a mean concentration of 2 micrograms/l on day 1 of lactation. Two ewes had detectable levels on day 2, but none was found in the milk thereafter. In the EGF-infused group, concentrations of EGF in colostrum were approximately 10 times higher than in the control ewes on day 1 of lactation and EGF was detected in mammary secretions on day 2 but not in subsequent milk samples. A range of 0.3-0.5% of the EGF infused appeared in mammary secretions over the first 2 d of lactation. No other differences were observed for colostrum composition, subsequent milk yield or composition between the two groups of ewes indicating that mammary gland development and function were unaffected. The levels of EGF observed in the mammary secretions of treated and control ewes indicate that the mammary glands accumulate and store EGF in the pre partum period.

Topics: Animals; Birth Weight; Body Weight; Colostrum; Eating; Epidermal Growth Factor; Female; Infusions, Intravenous; Lactation; Male; Mammary Glands, Animal; Milk; Pregnancy; Pregnancy, Animal; Radioimmunoassay; Sheep

The present study on the rat shows that i.v. administration of the proteinase inhibitor aprotinin reduces the urinary output of immunoreactive epidermal growth factor (EGF) while the amount of immunoreactive EGF in the kidneys is increased. This indicates that the EGF-precursor in the rat kidney in vivo is processed by an aprotinin inhibitable proteinase. EGF is produced in the kidneys as a precursor with a molecular weight of approximately 130 kDa. In rat urine, nanomolar amounts of 6 kDa EGF are excreted per 24 h together with small amounts of high molecular weight forms of EGF. During i.v. administration of aprotinin the median urinary output of immunoreactive EGF is reduced to 15% of the excretion of control rats (23 pmol/2 h versus 157 pmol/2 h, P less than 0.001). Especially the excretion of 6 kDa EGF is reduced (median excretion 12 pmol/2 h versus 134 pmol/2 h, P less than 0.001). The amount of immunoreactive EGF in the kidney tissue is increased after aprotinin administration (median amount 0.11 pmol EGF/mg protein versus less than 0.04 pmol EGF/mg protein, P less than 0.001). Neither the creatinine clearance, the total urinary protein output, nor the volume of urine produced was affected by aprotinin.

Topics: Animals; Aprotinin; Body Weight; Chromatography, Gel; Creatinine; Diuresis; Epidermal Growth Factor; Female; Immunohistochemistry; Kidney; Membrane Proteins; Rats; Rats, Inbred Strains

1. The effects of EGF administered subcutaneously on the intestinal cessation of macromolecular transmission and sucrase development were investigated in suckling rats and compared with those on hydrocortisone-treated pups. 2. In the EGF-treated pups, intestinal absorptive response of IgG was suppressed 50% whereas, the sucrase activity was not affected. In the hydrocortisone-treated pups, the absorptive response was inhibited completely, while sucrase activity was induced precociously. 3. The characteristics of intestinal cessation was morphologically observed at the jejunal epithelial cells in EGF and hydrocortisone-treated pups. 4. These results suggest that EGF affects the maturation of gastrointestinal function in a manner different from that of glucocorticoid hormones.

Topics: Animals; Animals, Newborn; Body Weight; Epidermal Growth Factor; Epithelial Cells; Epithelium; Hydrocortisone; Immunoglobulin G; Intestinal Mucosa; Intestines; Macromolecular Substances; Rats; Rats, Inbred Strains; Sucrase

We previously demonstrated that the antitumor efficacy of various antitumor agents such as 5-fluorouracil and cisplatin against experimental solid tumors was enhanced by pre- or simultaneous administration of human epidermal growth factor (hEGF). In the present study, the combined therapy by hEGF and mitomycin C (MMC) as an antitumor agent was studied in A431 solid tumor-bearing mice to determine the dosage schedule of hEGF. When MMC alone was injected intraperitoneally (2 mg/kg) every 7th day to the tumor-bearing mice, tumor weights increased to 2138 +/- 285 mg from 282 +/- 41 mg during 22 d. Tumor weight in every day treatment of hEGF alone for 21 d increased to the same extent in the treatment by MMC alone. On the other hand, the increase of the solid tumor weight in the every day treatment and in the every 7th day treatment of hEGF, in combination with the every 7th day administration of MMC, were as follows; from 282 +/- 41 mg to 1522 +/- 357 mg (71.2 +/- 16.7% of MMC alone) and from 280 +/- 44 mg to 1245 +/- 150 mg (58.2 +/- 7.0% of MMC alone), respectively, demonstrating a greater antitumor potency of MMC in the combination with the every 7th day treatment of hEGF. Both combined therapies did not affect the toxicity of MMC as evaluated by decrease in nontumorous body weight. Single subcutaneous administration of hEGF to A431 tumor-bearing mice caused the decrease of the binding capacity of hEGF to A431 tumor cells by 80% 24 h after the administration.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Antineoplastic Agents; Body Weight; Drug Administration Schedule; Drug Therapy, Combination; Epidermal Growth Factor; ErbB Receptors; Humans; Male; Mice; Mice, Inbred BALB C; Mitomycin; Mitomycins; Neoplasm Transplantation; Neoplasms, Experimental; Transplantation, Heterologous

Intestinal tissue mass was significantly reduced throughout the gastrointestinal tract (p less than 0.001) of intravenously fed (TPN) rats. Urogastrone-epidermal growth factor, (URO-EGF), reversed these changes. Although plasma enteroglucagon and gastrin levels showed a small increase with URO-EGF, this was far less than the gut tissue weight change, suggesting that it was unlikely that they were involved in modulating the proliferative response of the intestine to URO-EGF. Peptide tyrosine tyrosine (PYY) levels were however significantly increased by URO-EGF, indicating that PYY may possibly have a role in the modulation of intestinal cell proliferation.

Topics: Animals; Body Weight; Digestive System; Epidermal Growth Factor; Gastrins; Gastrointestinal Hormones; Glucagon-Like Peptides; Male; Organ Size; Parenteral Nutrition, Total; Peptide YY; Peptides; Rats; Rats, Inbred Strains

A progressive increase in intestinal 59Fe3+ absorption was observed on oral feeding of mice with physiological doses of EGF/UGO. Maximal changes were apparent after 3d and appeared to be dose-dependent. In addition to a small increase in intestinal cell proliferation, as reflected by increased ornithine decarboxylase activity, EGF/UGO-feeding increased mucosal permeability (evaluated with [51Cr]-EDTA): the latter could account for the increase in iron absorption. Sialoadenectomy, to remove the major source of endogenous EGF/UGO, had no appreciable effect on the intestinal absorption of iron.

Topics: Administration, Oral; alpha-Glucosidases; Animals; Body Weight; Cell Membrane Permeability; Drinking Behavior; Epidermal Growth Factor; Erythrocyte Indices; Intestinal Absorption; Intestinal Mucosa; Iron; Male; Mice; Mice, Inbred Strains; Ornithine Decarboxylase; Submandibular Gland

The protein molecule epidermal growth factor (EGF) exerts powerful effects on mouse physical development, since repeated subcutaneous administrations of murine EGF (3.5 mg/kg, from postnatal day 2 to postnatal day 10) cause precocious eyelid opening (as early as day 8 instead of day 13 in control littermates receiving 3.5 mg/kg cytochrome c) and precocious eruption of the lower incisors (day 6 instead of day 8). By contrast, the same EGF treatment retards both the rate of body growth and the full appearance of several neurobehavioral signs of maturation, such as righting and grasping responses. Neonatal mice receiving 5 mg/kg murine nerve growth factor (NGF) under the same treatment schedule, although showing a significant retardation in body weight gain, exhibited only limited changes in neurobehavioral maturation. Specifically, the appearance of slow and swift righting, response to strong tactile stimulation, hindlimb and forelimb grasping, pole grasping, and vertical screen and screen climbing were significantly retarded by EGF and slightly advanced by NGF (the only significant NGF effect was an acceleration of swift righting maturation). Polypeptide growth factors seem to play an important role in physical and neurobehavioral development of altricial rodents, orchestrating the relative maturation of different tissutal targets on different developmental stages.

Topics: Aging; Animals; Animals, Newborn; Behavior, Animal; Body Weight; Epidermal Growth Factor; Male; Mice; Nerve Growth Factors; Nervous System; Reference Values

The present experiments were undertaken to confirm the recent suggestion that epidermal growth factor (EGF) can have both retarding and accelerating effects on development, using a greater number of developmental indices than hitherto; to extend such studies to another species, the golden hamster, and to compare the responses of males and females. On each of days 0-3, one male and one female rat pup from each of 16 litters of 6 pups were injected subcutaneously with human EGF (0.5 micrograms/g body weight), one male and one female with vehicle, and the remaining two pups were not injected. As expected, EGF accelerated incisor eruption and eye-opening. However, EGF retarded the detachment of the pinna and the appearance of the auditory startle response. Free-fall righting was little affected. Hamster litters were left undisturbed till day 7 to minimise infanticide. Thereafter, experimental design was as far as possible the same as for the rats. Pups from 18 litters were injected on days 7-10. EGF advanced eye-opening, but retarded auditory startling, vaginal opening and the weaning growth spurt. Free-fall righting was unaffected. Hence, EGF had similar accelerating and retarding effects on development in both rats and hamsters. Also, these effects were the same in males and females for most indices.

Topics: Analysis of Variance; Animals; Body Weight; Cricetinae; Epidermal Growth Factor; Female; Growth; Male; Mesocricetus; Rats; Rats, Inbred Strains; Reflex, Startle; Tooth Eruption; Vagina

Topics: Animals; Animals, Newborn; Body Weight; Dioxins; Epidermal Growth Factor; Eye; Female; Male; Mink; Polychlorinated Dibenzodioxins; Tooth Eruption

Somatic growth retardation was studied in neonatal Sprague-Dawley rats following treatment with exogenous epidermal growth factor (EGF). Dose-response data are presented for the first 2 days of postnatal life relating log EGF dose (range 50 to 1000 ng per gram body weight) to incremental daily weight gain. Regression analysis indicated that the effect of EGF to retard somatic growth was not cumulative, and, in fact, the same dose of EGF had less effect on the second day of life than on the first. Concomitant with its ability to retard growth, EGF elicited a transient cutaneous reaction characterized by a marked alteration in skin viscoelasticity and temperature. Neonatal rats treated with exogenous EGF exhibited: (1) a dose-dependent reduction in skin redundancy measured by decrease in the height of the dorsal skinfold; (2) a diminution in integumental water content determined by wet weight/dry weight ratios and relative tissue specific gravities; and (3) a rapid fall in midscapular skin temperature within 60 minutes of systemic administration of EGF. Both the EGF-elicited cutaneous reaction and the ability of EGF to retard somatic growth disappeared by the end of the second week of life. Administration of human biosynthetic EGF resulted in responses identical to the purified mouse protein. In summary, the pharmacological effects of EGF to retard somatic growth in the newborn rodent are confined to the immediate neonatal period and are preceded by transient alteration in skin temperature and cutaneous biomechanical properties.

Topics: Animals; Animals, Newborn; Body Weight; Dose-Response Relationship, Drug; Elasticity; Epidermal Growth Factor; Rats; Rats, Inbred Strains; Skin; Skin Physiological Phenomena; Skin Temperature; Viscosity

Administration of anti-EGF serum to newborn mice led to delay of eyelid opening and incisor tooth eruption, acceleration of hair growth and delay of weight gain. These results indicate that in the first week after birth EGF still has a physiological function, which can be abrogated by anti-EGF serum.

Topics: Animals; Animals, Newborn; Body Weight; Cell Differentiation; Ear; Epidermal Cells; Epidermal Growth Factor; Eyelids; Hair; Immunologic Techniques; Mice; Tooth

Epidermal growth factor (EGF) has been shown to be present in the milk of several species, including the rat, and to have gastrointestinal effects when given parenterally or orally in pharmacologic doses. We investigated the effect of enteral EGF in physiologic doses on the small intestine and colon of suckling rats. Serum thyroxine (T4) levels were also measured. Rats were gavage-fed by hand with an artificial formula with or without added EGF every 3 h from 11 to 14 days of age. Intake was adjusted to deliver 30 kcal/100 g b.wt./day of formula and 16 micrograms/kg/day of EGF approximating the daily caloric intake, and about twice the estimated daily EGF intake for suckling rats. Weight gain did not differ between groups (fed EGF: 3.8 + 0.2 g; not fed EGF: 3.7 + 0.1 g). The protein content of the whole colon of rats fed an EGF-containing formula was significantly lower and the DNA content significantly higher, than in rats fed formula without added EGF. The protein/DNA ratio was therefore markedly higher in the animals fed formula without added EGF; these effects were most evident in the distal colon. In contrast, there was no effect of EGF on small intestinal protein and DNA content; lactase, sucrase, and maltase activities were likewise unaffected, as was serum T4. These data suggest a physiologic role for breast milk EGF in the development of the suckling rat colon.

Topics: Animals; Animals, Suckling; Body Weight; Epidermal Growth Factor; Intestine, Large; Intestine, Small; Rats; Rats, Inbred Strains

Effects of advancing age on responsiveness to triiodothyronine (T3) or dihydrotestosterone (DHT) by granular convoluted tubule (GCT) cells in submandibular glands were studied in C57BL/6NNia female mice of 4, 12, and 24 months of age. In untreated mice, absolute GCT volume and the frequency of cells strongly immunostained for EGF increased with age. Concentrations of EGF rose fourfold. Both T3 and DHT had inductive effects at each age: GCT cells were enlarged, contained more granules, and stained very strongly for EGF; EGF concentrations and the volume of GCTs also increased. However, the pattern of induction differed with age for the two hormones. After T3 treatment EGF concentration declined with age with respect to the degree of induction over same age control levels. By contrast, after DHT treatment the level of induction of EGF over control levels was the same at all three ages. The pattern of aging of GCT cells and their responsiveness to T3 or DHT in female mice differ from that previously reported for males.

Topics: Aging; Animals; Body Weight; Cytoplasmic Granules; Dihydrotestosterone; Epidermal Growth Factor; Female; Mice; Mice, Inbred C57BL; Organ Size; Submandibular Gland; Triiodothyronine

The effect of biosynthetic human epidermal growth factor (Bh-EGF) as well as mouse EGF on postnatal development of mice of ICR strain was examined. Daily administration of Bh-EGF (0.01, 0.1, and 1.0 microgram X g body wt-1 X day-1) for 30 consecutive days postpartum caused a clearly dose-dependent increase in their body weight. Furthermore, in addition to the well-known premature eyelid opening and early tooth eruption, we have also observed precocious opening of the vagina among treated females. As far as the accelerated growth rate as reflected in their body weight gain was concerned, daily administration for only five consecutive days postpartum was just as effective as the above noted 30 consecutive daily injections. As to the precocious vaginal opening, however, the susceptible 5-day-period was found to be 14-18 days after the parturition. Some of those treated females also entered the estrous cycle precociously, a few days after the precocious opening of their vagina. The microscopic examination of various organs from treated males and females revealed no apparent pathological changes. As far as the above noted effects of EGF were concerned, Bh-EGF, which is xenogenic to mice, was as potent as mouse EGF.

Topics: Animals; Animals, Newborn; Body Weight; Epidermal Growth Factor; Female; Male; Mice; Mice, Inbred ICR; Reaction Time

The effect of epidermal growth factor (EGF) on cellular differentiation of the neonatal mouse mandibular incisor was examined autoradiographically using tritiated thymidine ([3H]TDR) and tritiated proline ([3H]PRO). On days 0 (day of birth), 1, and 2, EGF was administered (3 micrograms/g body wt) sc to neonates. Mice were killed on Days 1, 4, 7, 10, and 13 after birth and were injected with either [3H]TDR or [3H]PRO 1 hr before death. [3H]TDR was used to analyze cell proliferation in eight cell types in the developing mouse incisor including upper (lingual) and lower (buccal) pulpal fibroblasts, preodontoblasts, inner and outer enamel epithelial cells (IEE and OEE), stratum intermedium (SI), stellate reticulum (SR), and periodontal ligament (PDL) fibroblasts. [3H]PRO was used to analyze protein synthesis in ameloblasts, and their secretion products (enamel and dentin), as well as PDL fibroblasts. The selected EGF injection scheme elicited acceleration of incisor eruption with minimal growth retardation. At Day 1, the upper and lower pulp, preodontoblasts, SI, and SR showed a significant decrease in labeling index (LI) 24 hr after a single EGF injection. After multiple injections (Days 0, 1, 2), two LI patterns were observed. In lower pulp, preodontoblasts, IEE, SI, SR, and OEE, a posteruptive change in LI was observed. In contrast, the upper pulp and PDL regions demonstrated a direct temporal relationship with eruption. Autoradiographic analysis with [3H]PRO indicated that EGF treatment caused significant increases in grain counts per unit area in ameloblast, odontoblast, and PDL regions studied. Significant differences were found in all four regions studied (ameloblasts, enamel, odontoblasts, dentin) at the 45-microns-tall ameloblast level as well as ameloblasts and odontoblasts at the 30-microns level at 13 days of age. The PDL demonstrated significant differences at all locations studied (base, 30 microns, 45 microns,) in 4-, 7-, and 13-day-old mice. Morphologically, EGF-treated groups demonstrated premature differentiation of ameloblasts and odontoblasts at the light microscopic level. The data indicate that EGF alters DNA and protein synthesis as well as differentiation patterns during the eruption process. While EGF affects both DNA and protein synthesis, the alteration of differentiation may be secondary to mitogenic effects on proliferative compartments. In order to determine the cellular target for EGF within the newborn mouse incisor, in vivo 12

Topics: Animals; Animals, Newborn; Autoradiography; Body Weight; Cell Differentiation; DNA; Epidermal Growth Factor; ErbB Receptors; Incisor; Mandible; Mice; Proline; Tooth Eruption

The effect of epidermal growth factor (EGF) on the postnatal development of the liver was examined. New Zealand White rabbits received 40 micrograms.kg-1.day-1 EGF from days 3 to 17 of age either intraperitoneally or orogastrically, whereas controls received saline. At days 18-20, animals underwent cannulation of the common duct using halothane anesthetic. Biliary output was measured directly for three 1-h periods: under basal conditions and in response to intravenous infusion of exogenous glycodeoxycholic acid at 0.75 and 1.5 mumol.min-1.kg-1, respectively. The bile salt pool size was measured by isotope dilution. Final mean body weight of intraperitoneal and orogastric groups did not differ from controls. Liver we weight, DNA, and protein content were significantly increased in intraperitoneally treated animals without morphological or biochemical evidence of fat deposition. Both intraperitoneal and orogastric EGF significantly increased bile salt secretion in the basal period and as a response to exogenous bile acid infusion. Bile flow was significantly increased in response to 1.5 mumol.min-1.kg-1 infusion of glycodeoxycholic acid. The bile salt pool was increased by both intraperitoneal and orogastric EGF. Administration of EGF resulted in a precocious development of glucokinase (EC 2.7.1.2) activity in the liver. EGF had no effect on serum cortisol, corticosterone, triiodothyronine, thyroxine, or free thyroxine levels. These findings suggest that in the neonatal period EGF can promote hepatic growth and maturation.

Topics: Animals; Bile; Bile Acids and Salts; Body Weight; DNA; Epidermal Growth Factor; Glucokinase; Glycodeoxycholic Acid; Lipid Metabolism; Liver; Organ Size; Proteins; Rabbits

The stomach of the naturally suckled rat pup was shown to grow rapidly during the first 24 h following delivery. Both absolute weight (p less than 0.001) and weight in proportion to body weight (p less than 0.001) increased. The stomachs of pups fed formula containing epidermal growth factor (EGF) were larger than those of their control littermates (p less than 0.05). These data support a role for milk EGF in the regulation of neonatal gut growth.

Topics: Administration, Oral; Animals; Animals, Newborn; Body Weight; Epidermal Growth Factor; Organ Size; Rats; Rats, Inbred Strains; Stomach

The shrew SMG contains a very high level of EGF. By heterologous radioreceptor assay, the EGF content was determined to be about 300 pmol/mg wet weight in the male. The content is sex dependent; in the female gland, it is only 4% of the male gland level. EGF level and EGF receptor content in other tissues showed a reciprocal distribution pattern with the parotid gland containing the second highest level of EGF and the liver containing the largest amount of EGF receptor. Shrew EGF is heat stable. It could induce early eyelid opening and incisor eruption in neonatal rat pups at a very low dose level. There is apparently no high molecular weight form of EGF in shrew tissues and body fluids. However, gel chromatography revealed that the foetus contained multiple forms of EGF. The contribution of a high EGF level to the active life in adult shrews and the exceptionally high growth rate in shrew pups are discussed.

Topics: Animals; Biological Assay; Body Weight; Chromatography, Gel; Epidermal Growth Factor; ErbB Receptors; Female; Male; Organ Size; Radioimmunoassay; Radioligand Assay; Receptors, Cell Surface; Shrews; Submandibular Gland; Tissue Distribution

Because epidermal growth factor (EGF) is rapidly bound and internalized into rat pancreas, stimulates uptake of tritiated thymidine, and increases pancreatic weight, a cocarcinogenic effect on pancreatic cancer seemed likely. Pancreatic adenocarcinomas were induced in 70 female Syrian hamsters by 19 weekly s.c. injections of N-nitrosobis(2-oxopropyl)amine (BOP) (10 mg/kg). From Wk 5 through Wk 8 of BOP injections, additional s.c. injections of EGF (5 micrograms every 3 days for 10 injections) were given to 45 animals, while 25 received saline solution. An additional group of 10 received EGF alone, and another 10 animals received saline solution alone (controls). Eleven wk later, the mean body weight of EGF-treated animals increased by 29% as compared with that of controls, and their mean pancreatic weight relative to body weight increased by 44% as compared with controls. The mean body weight of EGF + BOP-treated animals increased by 10%, and their pancreatic weight relative to body weight increased by 22% as compared with that of animals treated with BOP alone. The incidence of pancreatic cancer in the EGF + BOP-treated animals was 75% versus 44% in those treated with BOP alone (P = 0.016). No tumors developed in either animals treated with EGF alone or control animals. EGF augments pancreatic carcinogenesis induced by BOP. The incidence of bronchial carcinomas doubles.

Topics: Adenocarcinoma; Animals; Body Weight; Bronchial Neoplasms; Carcinogens; Cocarcinogenesis; Cricetinae; Epidermal Growth Factor; ErbB Receptors; Female; Mesocricetus; Nitrosamines; Oncogenes; Pancreatic Neoplasms; Receptors, Cell Surface; Receptors, Platelet-Derived Growth Factor

To evaluate the effects of epidermal growth factor (EGF) in dietary milk, a new method of delivering an artificial (EGF-deficient) formula was developed using 42 rat pups, 1-14 days of age. In a second study the effect of EGF was evaluated in suckling rats from 3-11 days of age: group 1, mother-fed; group 2, mother-fed plus daily injections of EGF (0.1 micrograms/g body weight); group 3, artificial milk fed with added EGF (62 ng/ml); and group 4, artificial milk fed without EGF. Each group consists of nine rats. In group 2 there was premature eye opening and tooth eruption and a significant reduction in body weight and weight of liver, kidney, thyroid, and thymus but an increase in length of the intestine and weights of stomach, pancreas, lung, and adrenal (p less than 0.04), when compared to group 1. Both groups 3 and 4 showed premature tooth eruption and eye opening, and their body weights and most organ weights were similar to group 2; exceptions were a smaller stomach, thyroid, thymus, lung, and adrenal, which were similar to those in group 1. In addition, intestinal length in groups 3 and 4 were similar to the mother-fed EGF-treated pups (group 2). There was no difference in intestinal length between the artificially fed pups, whether or not they received oral EGF. These findings demonstrate a new and effective technique of artificial feeding and suggest that the increase in intestinal length caused by injections of EGF (0.1 micrograms/g body weight) can also be induced by feeding an artificial milk with or without physiologic levels of EGF.

Topics: Age Factors; Animals; Animals, Suckling; Body Weight; Enteral Nutrition; Epidermal Growth Factor; Food, Formulated; Organ Size; Rats

The ability of exogenous mouse epidermal growth factor (EGF) (500 ng/g body weight/day) to retard somatic growth and to alter the timing of integumental maturation was investigated in the newborn rat. The immediate postnatal period (days 0-3) was identified as the critical time for elicitation of EGF effects. Somatic growth retardation produced by EGF persisted through weaning (day 20) and was asymmetric with maximal organ growth retardation present in liver and kidney and with relative sparing of heart and brain. Treatment of newborn rats with EGF on postnatal days 0-3 advanced the mean time of eyelid opening by 146 versus 31 h for tooth eruption. In contrast, EGF delayed opening of the external ear canal by approximately 48 h. EGF-treated pups thus exhibited a rearrangement in the normal sequence of craniofacial development. In summary, these data provide new information on the critical time of EGF response in the rat, the existence of an asymmetric pattern of organ growth retardation following perinatal EGF exposure, and the ability of EGF to retard morphogenesis of the external ear.

Topics: Animals; Animals, Newborn; Body Weight; Epidermal Growth Factor; Female; Growth; Growth Inhibitors; Male; Mice; Organ Size; Rats; Rats, Inbred Strains

We investigated the influence of transforming growth factor-beta (TGF-beta) on DNA synthesis in human fetal fibroblasts, as measured by the incorporation of [3H]thymidine and cell replication. In serum-free medium, without additional peptide growth factors, TGF-beta had no action on thymidine incorporation. However, in the presence of 0.1% v/v fetal calf serum, TGF-beta exhibited a bi-functional action on the cells. A dose-dependent stimulation of [3H]thymidine incorporation, and an increase in cell number, occurred with fibroblasts established from fetuses under 50 g body weight, with a maximum stimulation seen at 1.25 ng/ml. For fibroblasts from fetuses of 100 g or greater body weight, TGF-beta caused a dose-related decrease in thymidine uptake with a maximal inhibition at 2.5 ng/ml, and a small decrease in cell number. When DNA synthesis was stimulated by the addition of somatomedin-C/insulin-like growth factor I, epidermal growth factor, or platelet-derived growth factor, their actions were potentiated by the presence of TGF-beta on cells derived from fetuses under 50 g body weight, but inhibited on cells obtained from the larger fetuses weighing more than 100 g. Similar results were found for changes in cell number in response to TGF-beta when stimulated by SM-C/IGF I. The ability of TGF-beta to modulate [3H] thymidine incorporation did not involve a change in the time required for growth-restricted cells to enter the S phase of the replication cycle. These data suggest that TGF-beta may exert either a growth-promoting or growth-inhibiting action on human fetal connective tissues in the presence of other peptide growth factors, which is dependent on fetal age and development.

Topics: Body Weight; Cell Count; Cell Division; Cells, Cultured; DNA; Dose-Response Relationship, Drug; Epidermal Growth Factor; Fetus; Fibroblasts; Gestational Age; Humans; Insulin-Like Growth Factor I; Peptides; Platelet-Derived Growth Factor; Thymidine; Transforming Growth Factors

Because of findings implicating thyroid and growth hormones in the regulation of urinary EGF concentration, we determined urine and kidney EGF concentrations and relative kidney weights in both sexes of 8 weeks old dwarf mutant mice of the Snell strain and their normal littermates. Both male and female dwarfs had subnormal urine and kidney EGF concentrations. A female greater than male sex difference in both concentrations was present in the normal mice, but not in the dwarfs. The male greater than female sex difference in relative kidney weight, which has been demonstrated in normal mice of the Swiss-Webster strain, was not present in the normal or dwarf Snell mice.

Topics: Aging; Animals; Body Weight; Epidermal Growth Factor; Female; Kidney; Male; Mice; Mice, Mutant Strains; Organ Size; Sex Factors

The effect of epidermal growth factor (EGF) on the ontogeny of the gastrointestinal tract was examined in New Zealand White rabbits. EGF, 40 micrograms X kg-1 X day-1, was administered to suckling animals from 3-18 days of age either intraperitoneally or orogastrically. Controls received saline. Animals were killed at 17-18 days of age. Body weight and wet weight of stomach, pancreas, and 10-cm segments of proximal, mid, and distal small intestine were measured. The total pancreas was homogenized for determination of protein, DNA, and amylase, and the intestinal mucosa was scraped, weighed, and homogenized for estimation of protein, DNA, sucrase, and lactase. While body weights were similar wet weight of stomach and pancreas were increased by intraperitoneal and orogastric EGF. Small intestinal wet weights were increased in all segments by intraperitoneal but not orogastric EGF, and both routes significantly increased mucosal DNA in the distal segment. EGF administered orogastrically induced precocious maturation of intestinal brush-border disaccharidase activities but had no effect on pancreatic amylase, whereas EGF administered intraperitoneally induced precocious maturation of pancreatic amylase but had no effect on brush-border disaccharidase activities. These findings suggest that both systemic and oral EGF play a role in regulating growth and postnatal maturation of the gastrointestinal tract.

Topics: Amylases; Animals; beta-Galactosidase; Body Weight; Cattle; Digestive System; Epidermal Growth Factor; Gastric Mucosa; Humans; Intestinal Mucosa; Intestines; Mice; Organ Size; Pancreas; Rabbits; Rats; Sheep; Stomach; Sucrase; Swine

Although the role of thyroid hormones in enhancing lung and brain maturation during the perinatal period is well established, the cellular mechanisms involved in these processes are incompletely understood. Hypothyroidism retards the development of fetal pulmonary insulin, neonatal pulmonary beta-adrenergic and neonatal brain insulin receptors. In this study, we investigated the effect of hypo- or hyperthyroidism on the development of neonatal brain and lung epidermal growth factor (EGF) receptors. The rabbit pups were rendered hypothyroid by adding 0.05% propylthiouracil to the drinking water starting at 23 days of gestation and thereafter. The neonatal hyperthyroid state was achieved by intramuscular administration of 100 micrograms/kg of synthroid to the rabbit doe on the 29th and 30th day of pregnancy. Neonatal plasma free thyroxine (T4) concentrations were quantitated by a radioimmunoassay. Brain and lung plasma membranes were isolated by differential centrifugation. EGF receptor characteristics were studied using 125I-EGF binding assays and Scatchard analysis. The plasma free T4 concentrations were 0.36 +/- (SEM) 0.02 (n = 6), p less than 0.01 (n = 7) and 1.76 +/- 0.1 (n = 6) ng/dl in the control, hypothyroid and hyperthyroid pups, respectively. The percent specific binding of 125I-EGF to 200 micrograms of brain plasma membrane (BPM) protein was significantly lower in the hypothyroid (0.62 +/- 0.03, n = 7, p less than 0.01), and higher in the thyroxine-treated (1.58 +/- 0.08, n = 6, p less than 0.01) group when compared to control (1.08 +/- 0.06, n = 6) animals. However, the percent specific binding of 125I-EGF to 100 micrograms of lung plasma membrane (LPM) protein was similar in all three groups (2.24 +/- 0.28, control; 2.01 +/- 0.5, hypothyroid, and 2.26 +/- 0.3, hyperthyroid). The number of EGF receptors per milligram of BPM protein (X 10(-10] were lower in the hypothyroid (2.24 +/- 0.03, n = 5) and higher in the hyperthyroid (6.6 +/- 0.02, n = 4) group when compared to control (4.4 +/- 0.05, n = 4) with no apparent difference in Kd. There was no difference in the number of EGF binding sites per milligram of LPM protein (X 10(-10] within the groups (6.6 +/- 0.8, n = 6, control; 7.9 +/- 0.4, n = 4, hypothyroid, and 7.3 +/- 0.3, n = 4, hyperthyroid). Presence of high affinity receptors for EGF in the neonatal brain as well as lung supports the hypothesis that EGF may play an important role in neonatal brain and lung maturation.(ABSTRACT TRUNCATED

Topics: 5'-Nucleotidase; Animals; Binding Sites; Body Weight; Brain; Cell Membrane; Epidermal Growth Factor; Female; Lung; Nucleotidases; Pregnancy; Protein Binding; Rabbits; Receptors, Cell Surface; Thyroid Hormones

Topics: Animals; Body Weight; Duodenal Neoplasms; Epidermal Growth Factor; Female; Male; Methylnitronitrosoguanidine; Mice; Mice, Inbred Strains; Saliva; Submandibular Gland

The proliferative activities of germinative cells of the wool follicles and the epidermis have been determined in sheep treated with epidermal growth factor (EGF). Infusions of 0.17-0.72 mg EGF/kg metabolic body weight (MBW) for 28 h resulted in marked declines in the mitotic indices (MI) of the follicle bulb cell populations 24 h after the beginning of treatment, the lowest values being recorded at 48 h. Follicular activity subsequently recovered and the MI returned to preinfusion levels after 3-8 days. The inhibition of fiber production resulting from the decline in bulb cell division caused the development of a break in the fleece. By contrast, the MI of the peripheral cells of the sebaceous gland acini and the basal cells of the epidermis increased after EGF treatment, reaching peaks 48-72 h after the beginning of infusion. The degree to which all of these responses were observed appeared to be approximately correlated with the amount of EGF administered.

Topics: Animals; Body Weight; Cell Division; Dose-Response Relationship, Drug; Epidermal Cells; Epidermal Growth Factor; Epidermis; Hair; Male; Mitotic Index; Sheep; Time Factors; Wool

To study the origin and regulation of urinary epidermal growth factor (U-EGF), we measured EGF in adult female mouse plasma, urine and kidney tissue. We also studied the effects of excision of the submandibular salivary gland (SMG) and, after SMG excision and sham operation, 10-day therapies with T4 (0.4 microgram/g daily), testosterone propionate (TP, 12.5 micrograms/g every 48 h), and SMG extract (25 micrograms EGF daily). We measured EGF with a specific liquid phase radioimmunoassay. The mean apparent urinary clearance was 150-fold higher for EGF than for urea. U-EGF was increased 24 h after the last sc injection of SMG extract. SMG excision caused a 2.2-fold increase in U-EGF and in apparent EGF clearance. T4 brought about a 1.5 to 1.75-fold increase in U-EGF while TP was without effect. Kidney EGF (K-EGF) responded to T4 and TP like U-EGF, but SMG excision and extract were without effect on K-EGF. We conclude that 1) the immunoassayable EGF in blood plasma and SMG-EGF do not appear to be major sources of U-EGF but plasma EGF may be a minor source, 2) kidney tissue appears not to be a major source of U-EGF, 3) production of U-EGF is activated by SMG excision, 4) T4 increases both U- and K-EGF while testosterone has no effect.

Topics: Animals; Body Weight; Epidermal Growth Factor; Female; Kidney; Mice; Mice, Inbred Strains; Organ Size; Submandibular Gland; Testosterone; Thyroxine; Tissue Extracts

Because epidermal growth factor (EGF) can modify cell proliferation in the gastrointestinal tract, effects of EGF were studied on the development of colonic, rectal, and anal neoplasms in male mice treated with 1,2-dimethylhydrazine (DMH) (20 mg/kg/wk for 20 weeks). DMH treatment caused a 13% increase in colonic RNA content, a 16% increase in DNA content, and 28% greater crypt depth. EGF (5 micrograms on alternate days during weeks 20 to 22) administered to DMH-treated mice produced no additional changes in colonic mucosa. At 30 weeks colorectal tumors were present in 13 of 20 mice treated with DMH (mean number of tumors per mouse 2.3 +/- 0.5) and 18 of 24 mice (mean 2.6 +/- 0.7) treated with DMH and EGF. Anal tumors were present in two of 20 DMH-treated mice (mean 0.1 +/- 0.07) but in eight of 24 DMH-EGF-treated mice (mean 0.33 +/- 0.1) (X2 = 4.84; p less than 0.05 for prevalence). Although EGF in this dose has no effect on the frequency of colorectal adenocarcinomas, the frequency of anal squamous cell carcinomas is increased more than three fold.

Topics: 1,2-Dimethylhydrazine; Adenoma; Animals; Anus Neoplasms; Body Weight; Carcinoma, Squamous Cell; Dimethylhydrazines; DNA, Neoplasm; Epidermal Growth Factor; Male; Methylhydrazines; Mice; RNA, Neoplasm

Epidermal growth factor-like activity has been detected by radioreceptor assay and radioimmunoassay in the developing chick embryo. Very little activity could be detected prior to Day 8 of embryonic life (hatching is at Day 21). A peak of EGF activity was detectable by both assays over Days 10 to 12. The EGF activity then fell to virtually undetectable levels during Days 14 to 17. A later rise in RRA detectable EGF like activity was then observed over Days 18-20. The EGF activity from a Day 11 embryo chromatographed on high-performance liquid chromatography as a single peak, with very high recovery of activity, at a later elution position than mouse EGF or human EGF.

Topics: Animals; Body Weight; Chick Embryo; Chromatography, High Pressure Liquid; Epidermal Growth Factor; Radioimmunoassay; Radioligand Assay; Time Factors

Neonatal hyperthyroidism (NH) in the rat is associated with permanent reductions in serum thyroxine (T4), triiodothyronine (T3), and thyroid-stimulating hormone (TSH) concentrations in the adult, changes suggestive of a hypothyroid state. In the adult NH rat, the thyrotroph appears to be more sensitive to the feedback effects of thyroid hormones. To determine whether thyroid hormone sensitive tissues retain their responsiveness to thyroid hormones, the long-term effects of NH on mouse submandibular gland (SMG) epidermal growth factor (EGF) content were examined. NH was induced in female mice by 20 daily subcultaneous injections of 0.4 microgram of T4 per gram of body weight. Control female mice received daily injections of vehicle alone. At 21 days of age, NH and control mice were sacrificed and SMG EGF content was measured by specific radioimmunoassay, SMG EGF content and concentration in 21-day-old NH mice exceeded that of control mice by 2400- and 1500-fold, respectively (P less than 0.001). SMG EGF content and concentration in adult (90-day-old) NH mice were slightly, but not significantly, lower than those of control mice. Mean SMG weight, however, was significantly decreased in adult NH mice (P less than 0.01). Interestingly, SMG content and concentration of EGF in adult NH mice were lower than in 21-day-old NH mice. After 5 days T4 treatment (16 micrograms/d) of adult mice, SMG weight in NH mice increased significantly (P less than 0.01) but was unchanged in control mice. SMG EGF content and concentration increased significantly in both adult NH and control mice (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Animals, Newborn; Body Weight; Epidermal Growth Factor; Hyperthyroidism; Mice; Reference Values; Submandibular Gland; Thyroxine

The development and maintenance of granular convoluted tubule cells in the mouse submandibular gland (SMG) and the production of renin-1, renin-2, and epidermal growth factor (EGF) by these cells are under complex hormonal control. Hypophysectomy causes profound involution and loss of renin activity in this gland. We have shown previously that T4 acts synergistically with 5 alpha-dihydrotestosterone (DHT) to restore SMG morphology and renin-2 activity in hypophysectomized female mice. Investigating the mechanism of T4 and DHT interaction in the hypophysectomized mouse proved impractical, and in the present study we have used genetically hypothyroid (hyt/hyt) mice that carry the structural gene for renin-1 but not for renin-2. Levels of SMG renin-1 and EGF in hyt/hyt mice were less than 4% of those in euthyroid (hyt/+) littermates. Administration of a pharmacological dose of T4 (2.5 micrograms/g BW X day, ip) to male hyt/hyt mice for 18 days restored SMG renin-1 and EGF to near-normal levels. The weights of SMG, seminal vesicle, and epididymis were also lower in hypothyroid mice and increased in response to T4. The effect on SMG renin-1 and EGF of either DHT (150 micrograms/g BW every other day, sc) or T4 (0.025-2.5 micrograms/g BW.day, ip) was blunted in female hyt/hyt mice. A combination of DHT and T4 (0.1 microgram/g BW.day) that restored total circulating T4 and T3 to physiological levels acted synergistically to increase SMG renin-1 and EGF. The administration of 2.5 micrograms T4/g BW.day plus DHT for 7 days increased the specific activity of SMG renin-1 and EGF to levels approaching those in euthyroid littermates given the same treatment. T4 (0.1 microgram/g BW.day) did not alter the quantity or sedimentation characteristics of high affinity androgen-binding protein in SMG from female hyt/hyt mice and induced SMG renin-1 in Tfm/Y mice. Thus, T4 does not appear to exert its effect via the androgen receptor. The administration of DHT and T4 to female hyt/hyt mice produced lower circulating levels of both T3 and T4 than the same dose of T4 given alone, suggesting that DHT does not act by enhancing the conversion of T4 to T3. This study demonstrates that the interaction of T4 and DHT is not a pharmacological phenomenon, but occurs at doses of T4 that restore serum T3 and T4 in female hyt/hyt mice to normal or near-normal levels.(ABSTRACT TRUNCATED AT 400 WORDS)

Topics: Androgens; Animals; Body Weight; Dihydrotestosterone; Drug Synergism; Epidermal Growth Factor; Female; Hypothyroidism; Male; Mice; Organ Size; Receptors, Androgen; Renin; Submandibular Gland; Thyroxine

Rats were kept undernourished from birth to 24 days of age. At 17 days of age, the undernourished animals were divided into two groups and then injected with either saline or epidermal growth factor (EGF; 20 micrograms/kg) once a day for 7 days. They were killed 12-14 h after the last injection at which time the animals were 24 days old. During the experimental period the undernourished animals were prevented from weaning. A well-nourished group (weaned) which was injected with saline from 17 to 24 days of age, was also included. Undernutrition by itself significantly decreased body weight and the weight of the oxyntic gland area, antrum, and small intestine. This was also accompanied by a parallel reduction in DNA, RNA, and protein content in the oxyntic gland and small intestine. However, administration of EGF to undernourished rats resulted in a partial reversal of the situation. In undernourished rats, EGF caused significant enhancements in body weight as well as the weight of the gastrointestinal tissues and their protein and nucleic acid content when compared with the saline-treated undernourished controls. Furthermore, the magnitude of stimulation was found to be greater in the oxyntic gland than in the small intestine following EGF administration. The antral or serum gastrin levels were not affected by EGF. In both saline- and EGF-treated undernourished rats, lactase, sucrase, and alkaline phosphatase activities (expressed as total or specific activity) were found to be significantly higher than in the well-nourished animals.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Animals, Newborn; Body Weight; Digestive System; DNA; Epidermal Growth Factor; Female; Gastric Mucosa; Intestinal Mucosa; Male; Nutrition Disorders; Parietal Cells, Gastric; Proteins; Rats; Rats, Inbred Strains; RNA

To understand the physiological role of plasma epidermal growth factor (EGF) we studied in adult female mice the effect of endocrine manipulations on serum EGF concentration (S-EGF). Starting 1 month after sham operation (sh) or excision (SX) of the submandibular salivary gland (SMG), groups of 6 mice were given sc injections of T4 (0.4 micrograms/g daily), testosterone propionate (TP, 25 micrograms/g every 48 h), T4 + TP, or SMG extract (20 micrograms EGF daily) for 10 days. They were exsanguinated via the abdominal vena cava on day 11. During treatment the SX mice gained 55% less weight and their S-EGF was 25% lower compared with the sh mice. Hormone effects were clear in the SX mice: T4 caused a 35% decrease in S-EGF and a 5-fold increase in SMG-EGF concentration. TP caused a 1.6-fold increase in S-EGF and a 6-fold increase in SMG-EGF. Twenty-four hours after the last injection of SMG extract S-EGF remained 1.6-fold elevated. We conclude that plasma EGF is largely independent of SMG, and is modified by hormones in ways different from known tissue effects. This is consistent with an endocrine role of EGF.

Topics: Animals; Body Weight; Epidermal Growth Factor; Female; Mice; Mice, Inbred Strains; Organ Size; Submandibular Gland; Testosterone; Thyroxine; Time Factors

The effects of the topical application and the intraperitoneal administration of epidermal growth factor (EGF) on the healing of epidermal wounds, and of partial-thickness scalds in rats and of corneal wounds in rabbits were evaluated. The parameters measured were the daily percentage body weight change, time to complete healing of the wounds, the evaporative water loss from the wound surface and the rate of new formation of epithelial cell layers on the epidermal and corneal wounds. Wounded animals treated with 0.9% NaCl were used as controls. After removal of the corneal epithelium the local application of EGF stimulated the regeneration process appreciably. No significant healing advantage from the treatment with EGF was observed, however, in epidermal wounds and partial-thickness scalds. The result does not warrant any clinical evaluation.

Topics: Animals; Body Water; Body Weight; Burns; Cell Division; Cornea; Corneal Injuries; Epidermal Growth Factor; Epidermis; Mice; Rabbits; Rats; Rats, Inbred Strains; Skin; Wound Healing

Mouse epidermal growth factor/urogastrone (EGF/UG), administered sc in a dose of 0.1 microgram/g BW twice daily for 3 days, increased intestinal weight per unit length, lactase specific activity, and net calcium transport in normal 2-week-old suckling rats, but had no effect on maltase or sucrase specific activity. In normal 3-week-old weanling rats, the intestinal function of which is essentially fully mature, EGF/UG had no effect. These results suggest that EGF/UG, either secreted endogenously or ingested in breast milk, may have a role in both the morphological and functional maturation of the suckling rat intestine.

Topics: Aging; alpha-Glucosidases; Animals; beta-Galactosidase; Body Weight; Calcium; Epidermal Growth Factor; Female; Intestinal Absorption; Intestine, Small; Organ Size; Rats; Rats, Inbred Strains; Sucrase

Because the submandibular salivary glands of male mice are rich in growth factors such as epidermal growth factor and nerve growth factor, and because there are sporadic reports of sialadenectomized mice showing growth retardation and endocrine abnormalities, we studied oxidative metabolism and fertility after submandibular sialadenectomy. Despite similar intake of food, male mice (n = 60) deprived of submandibular saliva, either by duct ligation or gland excision, initially weighed 12-13% less than the sham controls and had a slower rate of growth (P less than 0.001). After 5 mo, mice with duct ligation caught up with the sham-operated mice, but the differences compared with submandibular-sialadenectomized mice were still apparent at 32 wk (P less than 0.001). The mean respiratory quotient of submandibular-sialadenectomized and duct-ligated mice was 0.71 instead of 0.88 as in the shams at 10, 20, and 30 wk after operation (P less than 0.01). No effect on fecundity was observed in either male or female mice following submandibular sialadenectomy.

Topics: Aging; Animals; Body Weight; Epidermal Growth Factor; Fertility; Growth; Male; Mice; Nerve Growth Factors; Oxygen Consumption; Submandibular Gland

The hormonal regulation of epidermal growth factor concentration in neonatal mouse skin and submandibular gland is examined by radioimmunoassay. The results show triiodothyronine but not dexamethasone effects an unequivocal elevation in skin EGF content. In contrast, the neonatal submandibular gland is hormonally unresponsive during this period. Combined therapy with T3 and dexamethasone produces precocious incisor eruption compared to the effect of either hormone alone. The mechanism of this synergistic acceleration of an EGF-related developmental event is unknown.

Topics: Animals; Body Weight; Dexamethasone; Drug Synergism; Epidermal Growth Factor; Mice; Skin; Submandibular Gland; Thyroxine; Tooth Eruption; Triiodothyronine

The growth of the first hair coat in male mice was studied during administration of epidermal growth factor (EGF). Injections of 1 or 4 micrograms EGF/g body weight for 14 consecutive days from birth resulted in the development of curved overhairs (monotrichs), caused a retardation in rate of growth in length of hair and a reduction in hair diameter and length of follicle bulb. Growth rate partially recovered after cessation of EGF treatment. However, some of the effects produced by injections of EGF during the formation of the first coat were detected in the second and third generations of hair. Since EGF also retarded rate of body growth, we compared the effect of EGF on hair growth with that of restricting food intake in neonatal mice during the development of the first coat. Hair growth was slowed in underfed animals but the effects were less marked than those found in EGF-treated mice of similar body weights.

Topics: Animals; Body Weight; Epidermal Growth Factor; Hair; Male; Mice; Peptides

Epidermal growth factor (EGF), and androgen-dependent polypeptide, occurs in high concentration in male mouse submandibular gland. Glands of adult male and female mice of six inbred strains (129/J, C57BL/6J, C58/J, SWR/J, RF/J, A/J) were assayed for EGF by radioimmunoassay. In all strains, the glands of males contained 30 to 500-fold more EGF than those of females. Furthermore, significant differences in EGF content were found among the various strains in both sexes, the highest amount of EGF was present in RF/J and the lowest in C57BL/6J, with a ratio of three in the males and four in the females of the two strains, respectively. Factors that effect EGF levels were analyzed further, using these two strains. EGF was measurable in the glands of mice of both strains at 21 days of age and increased rapidly thereafter, up to 14 weeks of age. Throughout postnatal development, the level of EGF was greater in the glands of RF/J mice than in those of the C57BL/6J animals. Thirty days after castration, the EGF levels were reduced by about 98% in both strains, but the strain difference was not abolished. Testosterone implants (1 mg in Silastic tube) in castrated mice induced EGF levels six- to ten-fold compared to castrates. Even in induced animals, which had similar plasma testosterone levels, as measured by radioimmunoassays, the difference in EGF levels between the two strains was manifest. Such a difference, however, was not seen after the daily administration of 5-alpha-dihydrotestosterone for 3-14 days. Immunocytochemical straining for EGF also indicated a higher concentration of the polypeptide in the glands of RF/J mice than in those of C57BL/6J animals, and confirmed the exclusive localization of EGF in the cells of the granular convoluted tubules (GCT). According to our morphometric analysis, in the glands of male RF/J mice the GCT compartment occupied a greater portion (8% greater, P less than 0.001) of the gland volume than in C57BL/6J mice. The difference in the relative GCT volumes in the glands of female mice of the two strains was, however, statistically not significant. There was no direct correlation between the amount of EGF and the relative volume of the GCTs in the two strains. The evidence obtained implies that strain difference in submandibular-gland EGF levels are determined genetically.

Topics: Aging; Animals; Body Weight; Castration; Dihydrotestosterone; Epidermal Growth Factor; Female; Male; Mice; Mice, Inbred Strains; Peptides; Radioimmunoassay; Sex Factors; Species Specificity; Submandibular Gland; Testosterone

Injection of epidermal growth factor (EGF) into 24-day rabbit fetuses (5 microgram, im or ip) induced accelerated maturation of the lung. On sacrifice at day 27, there was greater distensibility and stability on deflation associated with the appearance of a complement of type II cells approaching that of the rabbit at term. EGF treatment had no demonstrable effect on body weight or lung weight in this group of animals. Saline-injected control fetuses were not affected significantly.

Topics: Animals; Body Weight; Epidermal Growth Factor; Epithelium; Female; Fetus; Lung; Organ Size; Peptides; Pregnancy; Pulmonary Alveoli; Rabbits; Total Lung Capacity