metallothionein and Acute-Disease

Treatment of patients with acute pancreatitis has greatly improved due to a better understanding of the pathophysiology of the disease. This pathophysiology includes the activation and release of pancreatic enzymes in the interstitium, the autodigestion of the pancreas, and a multiple organ dysfunction after their release into the systemic circulation. Moreover, significant evidence exists that synthesis and release of proinflammatory cytokines and chemokines are also responsible for the local injury and systemic dispersion of the inflammation. The use of knockout mice devoid of active pro- or anti-inflammatory mediators allows examination of the effects of a specific cytokine without any drawbacks induced by pharmacological manipulations. The results obtained from these genetically modified mice show that numerous mediators have a major role in the pathophysiology of acute pancreatitis. They also clearly demonstrate that a single genetic deletion cannot completely prevent the occurrence of pancreatic or distant organ injury. However, the fact that the immune system is characterized by redundancies of ligands and receptors complicates the full understanding of each report. The utility of such experimental models might have limitations, and a full extrapolation of experimental data from genetically modified mice to humans must be done with caution.

Topics: Acute Disease; Animals; Cathepsin B; Cytokines; Disease Models, Animal; Intercellular Adhesion Molecule-1; Metallothionein; Mice; Mice, Knockout; Pancreatitis; Receptors, CCR1; Receptors, Chemokine; Receptors, Neurokinin-1; Superoxide Dismutase

Metallothioneins (MTs) are known to participate in protection against oxidative stress. This study assessed the effects of MT-I&II gene knockout on methotrexate (MTX)-induced bone damage in growing mice. MT-I&II knockout (MT⁻/⁻) and wild type (MT⁺/⁺) male mice were injected with saline or 12.5 mg kg⁻¹ MTX for three consecutive days. MTX treatment was shown to cause more severe damage in MT⁻/⁻ mice when compared to MT⁺/⁺ mice, as demonstrated by the more obvious thinning of growth plate, reduced proliferation and increased apoptosis of chondrocytes, and reduced metaphysis heights in the knockout mice. Analysis of total liver glutathione (the most abundant intracellular antioxidant) also revealed significant lower glutathione levels in all MT⁻/⁻ mice. In conclusion, MT⁻/⁻ mice were more susceptible than MT⁺/⁺ mice to MTX-induced bone damages, which may be associated with the reduction of basal antioxidant defence, suggesting a protective role of MTs in the growing skeleton against damages caused by MTX chemotherapy.

Topics: Acute Disease; Animals; Antimetabolites, Antineoplastic; Antioxidants; Apoptosis; Bone Development; Cell Proliferation; Chondrocytes; Glutathione; Growth Plate; Male; Metallothionein; Methotrexate; Mice; Mice, Inbred C57BL; Mice, Knockout; Oxidative Stress; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger

Inflammatory bowel diseases (IBDs) are recurrent intestinal pathologies characterized by a compromised epithelial barrier and an exaggerated immune activation. Mediators of immune cell infiltration may represent new therapeutic opportunities. Metallothioneins (MTs) are stress-responsive proteins with immune-modulating functions. Metallothioneins have been linked to IBDs, but their role in intestinal inflammation is inconclusive. We investigated MT expression in colonic biopsies from IBDs and acute infectious colitis patients and healthy controls and evaluated MT's role in experimental colitis using MT knockout mice and anti-MT antibodies. Antibody potential to target extracellular MT and its mechanism was tested in vitro. Biopsies of patients with active colitis showed infiltration of MT-positive cells in a pattern that correlated with the grade of inflammation. MT knockout mice displayed less severe acute dextran sulphate sodium (DSS)-induced colitis compared to congenic wild-type mice based on survival, weight loss, colon length, histological inflammation and leukocyte infiltration. Chronic DSS-colitis confirmed that Mt1 and Mt2 gene disruption enhances clinical outcome. Blockade of extracellular MT with antibodies reduced F4/80-positive macrophage infiltration in DSS- and trinitrobenzene sulphonic acid-colitis, with a tendency towards a better outcome. Whole-body single-photon emission computer tomography of mice injected with radioactive anti-MT antibodies showed antibody accumulation in the colon during colitis and clearance during recovery. Necrotic and not apoptotic cell death resulted in western blot MT detection in HT29 cell supernatant. In a Boyden chamber migration assay, leukocyte attraction towards the necrotic cell supernatant could be abolished with anti-MT antibody, indicating the chemotactic potential of endogenous released MT. Our results show that human colitis is associated with infiltration of MT-positive inflammatory cells. Since antibody blockade of extracellular MT can reduce colitis in mice, MT may act as a danger signal and may represent a novel target for reducing leukocyte infiltration and inflammation in IBD patients.

Topics: Acute Disease; Adolescent; Adult; Aged; Aged, 80 and over; Animals; Antibodies; Apoptosis; Biopsy; Case-Control Studies; Chemotaxis, Leukocyte; Chronic Disease; Colitis; Colon; Dextran Sulfate; Disease Models, Animal; Female; HT29 Cells; Humans; Macrophages; Male; Metallothionein; Mice; Mice, Inbred C57BL; Mice, Knockout; Middle Aged; Necrosis; Severity of Illness Index; Signal Transduction; Time Factors; Trinitrobenzenesulfonic Acid; Young Adult

To study the acute and subacute pulmonary toxicity of colloidal silver nanoparticles (Ag-NPs), 0 or 100 ppm of Ag-NPs were instilled intratracheally in mice. Cellular and biochemical parameters in bronchoalveolar lavage fluid (BALF) and histological alterations were determined 1, 3, 7, 15, and 30 days after instillation. Ag-NPs induced moderate pulmonary inflammation and injury on BALF indices during the acute period; however, these changes gradually regressed in a time-dependent manner. Concomitant histopathological and laminin immunohistochemical findings generally correlated to BALF data. Superoxide dismutase and metallothionein expression occurred in particle-laden macrophages and alveolar epithelial cells, which correlated to lung lesions in mice treated with Ag-NPs. These findings suggest that instillation of Ag-NPs causes transient moderate acute lung inflammation and tissue damage. Oxidative stress may underlie the induction of injury to lung tissue. Moreover, the expression of metallothionein in tissues indicated the protective response to exposure to Ag-NPs.

Topics: Acute Disease; Administration, Inhalation; Animals; Colloids; Disease Models, Animal; Epithelial Cells; Lung; Lung Diseases; Macrophages; Male; Metal Nanoparticles; Metallothionein; Mice; Mice, Inbred ICR; Silver; Time Factors

The aims of the present studies were to measure the concentrations of zinc (Zn), copper (Cu), and metallothionein and the Cu/Zn superoxide dismutase activity as elements engaged in an essential manner in the prooxidative and antioxidative balance of organism and to demonstrate the degree to which metallothionein and Cu/Zn superoxide dismutase are involved in the inflammatory processes occurring in the pancreas.. The concentration of metallothionein was measured by immunoenzymatic method. Serum Cu/Zn superoxide dismutase activity was determined using a commercial test. The measurements of Zn and Cu concentrations in serum were assessed with the use of flame atomic absorption spectrometry.. Lowered serum Zn concentration and higher Cu level were observed in the serum of patients with chronic exacerbated pancreatitis and chronic pancreatitis. The significant increase of metallothionein concentration and Cu/Zn superoxide dismutase activity was observed in the blood of patients with chronic exacerbated pancreatitis and chronic pancreatitis. In slices of the pancreas during pancreatitis, we observed in immunohistochemical reaction the variable involvement of Cu/Zn superoxide dismutase and metallothionein.. The results presented in these studies indicate an essential and variable involvement of antioxidants such Cu/Zn superoxide dismutase and metallothionein and disordered Cu and Zn homeostasis depending on the progression of inflammatory processes in patients with pancreatitis.

Topics: Acute Disease; Adult; Aged; Case-Control Studies; Copper; Female; Humans; Immunohistochemistry; Male; Metallothionein; Middle Aged; Pancreatitis; Pancreatitis, Chronic; Superoxide Dismutase; Zinc

Metallothionein (MT) is a small molecular weight protein possessing metal binding and free radical scavenging properties. We hypothesized that MT-1/MT-2 null (MT(-/-)) mice would display exacerbated soleus muscle atrophy, oxidative injury, and contractile dysfunction compared with the response of wild-type (WT) mice following acute spinal cord transection (SCT). Four groups of mice were studied: WT laminectomy, WT transection, MT(-/-) laminectomy (MT(-/-) lami), and MT(-/-) transection (MT(-/-) trans). Laminectomy animals served as surgical controls. Mice in SCT groups experienced similar percent body mass (BM) losses at 7 days postinjury. Soleus muscle mass (MM) and MM-to-BM ratio were lower at 7 days postinjury in SCT vs. laminectomy mice, with no differences observed between strains. However, soleus muscles from MT(-/-) trans mice showed reduced maximal specific tension compared with MT(-/-) lami animals. Mean cross-sectional area (microm(2)) of type I and type IIa fibers decreased similarly in SCT groups compared with laminectomy controls, and no difference in fiber distribution was observed. Lipid peroxidation (4-hydroxynoneal) was greater in MT(-/-) trans vs. MT(-/-) lami mice, but protein oxidation (protein carbonyls) was not altered by MT deficiency or SCT. Expression of key antioxidant proteins (catalase, manganese, and copper-zinc superoxide dismutase) was similar between the groups. In summary, MT deficiency did not impact soleus MM loss, but resulted in contractile dysfunction and increased lipid peroxidation following acute SCT. These findings suggest a role of MT in mediating protective adaptations in skeletal muscle following disuse mediated by spinal cord injury.

Topics: Acute Disease; Animals; Antioxidants; Catalase; Disease Models, Animal; Laminectomy; Lipid Peroxidation; Male; Metallothionein; Mice; Mice, Knockout; Muscle Contraction; Muscle Fibers, Fast-Twitch; Muscle Fibers, Slow-Twitch; Muscle Strength; Muscle, Skeletal; Muscular Atrophy; Oxidative Stress; Protein Carbonylation; Spinal Cord Injuries; Superoxide Dismutase; Thoracic Vertebrae

Topics: Acute Disease; Animals; Calcium Signaling; Cyclic GMP; Endothelial Cells; Humans; Hypoxia; Metallothionein; Mice; Mice, Knockout; Models, Biological; Nitric Oxide; Nitrosation; Protein Kinase C; Protein Processing, Post-Translational; Pulmonary Artery; Rats; Signal Transduction; Vascular Resistance; Vasoconstriction; Zinc

A previous study (Oliver, J.R., Mara, T.W., Cherian, M.G. 2005. Impaired hepatic regeneration in metallothionein-I/II knockout mice after partial hepatectomy. Exp. Biol. Med. 230, 61-67) has shown an impairment of liver regeneration following partial hepatectomy (PH) in metallothionein (MT)-I and MT-II gene knockout (MT-null) mice, thus suggesting a requirement for MT in cellular growth. The present study was undertaken to investigate whether MT may play a similar role in hepatic injury and regeneration after acute treatment with thioacetamide (TAA). Hepatotoxicity of TAA is caused by the generation of oxidative stress. TAA was injected ip to both wild-type (WT) and MT-null mice. Mice were killed at 6, 12, 24, 48, 60, and 72 h after injection of TAA (125 mg/kg) or 48 h after injection of saline (vehicle control), and different parameters of hepatic injury were measured. The levels of hepatic lipid peroxidation were increased at 12 h in both types of mice; however, lipid peroxidation was significantly less in WT mice than MT-null mice at 48 h after injection of TAA. Analysis of hepatic glutathione (GSH) levels after TAA injection showed depletion of GSH at 12 h in WT mice and at 6 h in MT-null mice; however, significantly more GSH was depleted early (6-24 h) in MT-null mice than WT mice. An increase in hepatic iron (Fe) levels was observed in both types of mice after injection of TAA, but Fe levels were significantly higher in MT-null mice than WT mice at 6-60 h. The levels of hepatic copper (Cu) and zinc (Zn) were significantly higher in WT mice than MT-null mice at 6-60 h for Cu, and at 24 h and 60 h for Zn, respectively. Histopathological examination showed hemorrhagic necrosis in the liver of both types of mice at 12-72 h, with hepatic injury being more prominent in MT-null mice than WT mice. The hepatic MT levels were increased in WT mice after injection of TAA, and were highest at 24-72 h. Immunohistochemical staining for MT in WT mice indicated the presence of MT in both nucleus and cytoplasm of hepatocytes at 24-72 h after TAA injection. Cell proliferation, as assessed by immunohistochemical staining for proliferating cell nuclear antigen, was detected mainly in the livers of WT mice at 48-72 h after TAA treatment. Hepatic proliferation index in MT-null mice was very low as compared to WT mice during liver regeneration after injection of TAA. These results show that the liver cells of MT-null mice with no functional MT are unable to regenerate afte

Topics: Acute Disease; Animals; Cell Proliferation; Chemical and Drug Induced Liver Injury; Glutathione; Iron; Lipid Peroxidation; Liver; Liver Regeneration; Metallothionein; Mice; Mice, Knockout; Necrosis; Thioacetamide

The present report is an attempt to investigate the influence of intraperitoneal and dietary cadmium exposure on the distribution of cadmium accumulation and induction of metallothionein gene expression in different tissues of the lizard Podarcis sicula. Cadmium accumulation in liver, kidney, ovary, brain and intestine was measured by atomic absorption spectrometry. Metallothionein gene induction was determined by dot blot analyses on the total RNA extracted from the same organs. Our data indicate that cadmium exposure results in significant cadmium uptake, but the patterns of this uptake varies with organ and exposure route. After a single intraperitoneal treatment, concentrations of cadmium and metallothionein transcript are positively correlated in kidney, liver and ovary. Following a dietary cadmium treatment, a positive correlation between the increase of metallothionein mRNA and cadmium accumulation is found in intestine, ovary and kidney, while no correlation is present in liver and brain.

Topics: Acute Disease; Animals; Cadmium; Cadmium Poisoning; Chronic Disease; Female; Gene Expression; In Situ Hybridization; Lizards; Metallothionein; RNA; Spectrophotometry, Atomic; Tissue Distribution

Cadmium chloride (CdCl(2)) is a nephrotoxicant that causes damage to the proximal tubular epithelium. In vivo, it increases the permeability of epithelial surfaces, while in vitro, it acts on active trans-epithelial ion transport. The purpose of this study was to investigate CdCl(2) effects on a porcine renal proximal tubular epithelial cell line (LLC-PK1), and, in particular, to identify sensitive endpoints revealing damage both at the epithelial barrier level and at the molecular level. After exposure of the cells to CdCl(2), trans-epithelial resistance (TER) decreased while paracellular permeability (PCP) increased, indicating a structural alteration of the junctional complex. At the molecular level, we observed an increase in protective proteins, such as metallothioneins (MTs) and heat shock proteins (HSP70), starting from 25 microM CdCl(2), together with alterations in cytoskeleton organization. Production of reactive oxygen species (ROS) was also evident, indicating cellular oxidative stress. Our data indicate that CdCl(2) toxicity can be detected at the barrier level and at the molecular level at low concentrations, at which cytotoxicity assays are unable to show any damage. Therefore, these endpoints should prove very useful in studying heavy metal-induced acute toxicity. Exposure of the cells to higher concentrations of CdCl(2) (50 microM) revealed the initiation of apoptosis, mediated by caspase-3.

Topics: Acute Disease; Animals; Apoptosis; Biological Transport; Blotting, Western; Cadmium Chloride; Cadmium Poisoning; Cell Survival; Epithelial Cells; Flow Cytometry; HSP70 Heat-Shock Proteins; Immunohistochemistry; Kidney Diseases; Kidney Tubules, Proximal; L-Lactate Dehydrogenase; LLC-PK1 Cells; Metallothionein; Reactive Oxygen Species; Swine

Rats injected with mercuric chloride develop an acute renal tubular necrosis with uremia, which is frequently lethal. Pretreatment for 3 or 7 days with a protein-free diet reduces the mortality, the clinical signs (tremor), and the severity of renal tubular necrosis, and ameliorates the uremic chemical findings in the serum. Similar results followed injection of a nephrotoxic amino acid, D-serine, after pretreatment with a protein-free diet. Indirect evidence suggests that induction of metallothionein may be involved, at least in the experiments with mercury. Acute uremia produced by nephrotoxic chemicals may be useful for further studies of the role of nutrition in uremia, while avoiding the surgical procedures and prolonged observations required for the "remnant kidney" models.

Topics: Acute Disease; Animals; Biomarkers; Body Weight; Diet, Protein-Restricted; Disease Models, Animal; Dose-Response Relationship, Drug; Injections, Subcutaneous; Kidney; Kidney Tubular Necrosis, Acute; Male; Mercuric Chloride; Metallothionein; Phosphates; Rats; Rats, Inbred Lew; Rats, Sprague-Dawley; Sucrose; Time Factors; Treatment Outcome; Urea; Uremia

The aim of this study was to investigate the role of metallothionein in cardiac transplants in relation to cytokines and allograft function. Recent studies have revealed an association of allograft dysfunction with elevated proinflammatory cytokines independent of cellular rejection. In animal experiments, cytokines induced overexpression of metallothionein, a low-molecular-weight protein implicated in cellular stress response.. In 105 consecutive biopsies from 15 patients during the first 3 months after heart transplantation, metallothionein expression was investigated immunohistochemically. Its relation to serum interleukin-6, tumor necrosis factor-alpha, interleukin-2 (IL-2), soluble interleukin-2 receptor rejection, and echocardiographic parameters was determined. Forty-three biopsies of 12 patients with idiopathic ventricular tachycardia served as controls.. Metallothionein expression was demonstrated in small vessels, cardiomyocytes, fibrocytes, and interstitial round cells. A positive relation between interleukin-6 levels and the number of metallothionein-positive small vessels (p < 0.028) was observed. Patients with lower serum IL-2 levels showed significantly higher numbers of metallothionein-positive small vessels (p < 0.043). Grafts with prolonged ischemic time (>150 minutes) showed a significantly higher myocardial metallothionein score (p < 0.021). Metallothionein expression was associated with lower fractional shortening, larger left ventricular end-systolic diameter, and lower mean arterial pressure but not with acute cellular rejection.. Metallothionein expression is associated with elevated interleukin-6 and decreased interleukin-2 serum levels and left ventricular allograft dysfunction in the absence of rejection.

Topics: Acute Disease; Biopsy; Cytokines; Echocardiography; Graft Rejection; Heart Transplantation; Humans; Immunohistochemistry; Immunosuppression Therapy; Linear Models; Metallothionein; Myocardial Ischemia; Myocardium; Statistics, Nonparametric; Tachycardia, Ventricular; Time Factors; Transplantation, Homologous

The aim of this study was to determine the lung levels of metallothionein (MT), a free radical scavenger, because oxygen-derivated free radicals (ODFRs) have been involved both in reperfusion injury of transplanted lungs and in cardiac or renal allograft destruction. First, MT localization was evaluated in 14 normal human lung biopsy specimens. Then, in lung transplant recipients, MT content in BAL fluid (BALF) and its transcription rate in alveolar macrophages (AMs) were determined. The BALFs of 69 patients were separated into six groups: lung transplant recipients in clinically stable condition (CSR), those with acute rejection (AR), asymptomatic cytomegalovirus infection (ACMV), cytomegalovirus pneumonitis (CMVP), bronchiolitis obliterans syndrome (BOS), and patients without transplants who served as control subjects (NTCs). In normal lungs, 83% of AMs were positively stained. MT staining was also observed in pleural endothelial cells and basal cells from bronchial epithelium. In lung transplant recipients, MT levels in BALF were significantly higher in patients with CSR, AR, ACMV, and CMVP compared with NTCs, while during BOS, MT had a significantly lower level compared with other lung transplant groups. However, no difference among groups was found concerning MT-II messenger RNA expression in AMs, showing that, as in normal lung, AMs are not the only cells that produce MT. These data report for the first time to our knowledge MT cell distribution in human lung with specific emphasis on its enhanced levels after lung transplantation, even in the absence of complication. Possible correlation among MT levels, ODFRs, cytokine levels, and corticosteroid treatment during complications of lung transplantation are discussed.

Topics: Acute Disease; Adrenal Cortex Hormones; Adult; Aged; Bronchiolitis Obliterans; Bronchoalveolar Lavage Fluid; Coloring Agents; Cytomegalovirus Infections; Endothelium, Vascular; Epithelium; Female; Free Radical Scavengers; Free Radicals; Gene Expression Regulation; Graft Rejection; Graft Survival; Humans; Interleukin-6; Lung; Lung Transplantation; Macrophages, Alveolar; Male; Metallothionein; Middle Aged; Pleura; Pneumonia, Viral; Reactive Oxygen Species; Reperfusion Injury; RNA, Messenger; Transcription, Genetic; Tumor Necrosis Factor-alpha

Oxidative stress has been proposed to play a role in the early events of acute pancreatitis, and metallothionein (MT) can provide protection against oxidative stress. Using transgenic mice, we characterized the effects of depletion of MT-I and -II, or overexpression of MT-I, on pancreatic responses during cerulein-induced acute pancreatitis. In MT-I/-II knockout mice, repeated injections of cerulein caused (a) higher serum amylase levels at 3 and 7 h after the initiation of acute pancreatitis; (b) earlier and stronger upregulation of oxidative stress-responsive genes, including heme oxygenase (HO)-1 and c-fos; and (c) exacerbated tissue damage (edema and polymorphonuclear neutrophil infiltration) compared with nontransgenic 129/SvCPJ mice. Total pancreatic glutathione (GSH + GSSG) content was similar between the knockout and nontransgenic 129/SvCPJ mice. Interestingly, during acute pancreatitis, CD-1 mice pretreated with L-buthionine-[S,R]-sulfoximine (BSO), which dramatically depleted pancreatic GSH, also had more severe pancreatitis, based on the same three criteria listed above, relative to untreated controls. No effects were observed with BSO treatment alone. Finally, during cerulein-induced acute pancreatitis, MT-I overexpressing transgenic mice (>20-fold increase in pancreatic MT-I content) had lower serum alpha-amylase levels between 7 and 24 h and delayed upregulation of HO-1 mRNA levels, but no difference in c-fos mRNA induction relative to the appropriate strain of nontransgenic mice. Diminished tissue damage (particularly cellular necrosis) was noted in these MT-I overexpressing transgenic mice. Total pancreatic GSH content was similar in these transgenic and nontransgenic mice during cerulein-induced acute pancreatitis. These studies suggest that pancreatic MT can function as an intracellular antioxidant as does GSH and that these intracellular antioxidants play a protective role during cerulein-induced acute pancreatitis.

Topics: Acute Disease; Amylases; Animals; Buthionine Sulfoximine; Ceruletide; Glutathione; Heme Oxygenase (Decyclizing); Male; Metallothionein; Mice; Mice, Knockout; Mice, Transgenic; Pancreas; Pancreatitis; Proto-Oncogene Proteins c-fos; RNA, Messenger

Oxidative stress and the inflammatory response may play roles in the pathogenesis of acute pancreatitis. Herein, we characterized pancreatic expression of oxidative stress-responsive genes [c-fos, heme oxygenase-1 (HO-1), and metallothionein-I (MT-I)] and cytokine genes [interleukin-1 beta (IL-1 beta), IL-6, and tumor necrosis factor-alpha (TNF-alpha)] during caerulein-induced acute pancreatitis in the mouse. c-fos, HO-1, and MT-I mRNAs were coordinately and rapidly (3-7 h) upregulated, and HO-1 and MT-I protein levels were increased slightly in the pancreas during acute pancreatitis. In addition, IL-1 beta, IL-6, and TNF-alpha mRNAs were rapidly (7 h) upregulated in the pancreas, and intrapancreatic IL-1 beta and IL-6 protein levels rapidly increased (3-fold and 6.4-fold, respectively) during acute pancreatitis. These studies suggest that oxidative stress and inflammation each occur in the pancreas during the early stages of acute pancreatitis. However, under a limited set of experimental conditions, we found that an insult that causes pancreatic oxidative stress (diethylmaleate) or one that induces an inflammatory response (bacterial lipopolysaccharide), or a combination of these agents, did not cause the changes characteristic of acute pancreatitis. Therefore, simply inducing oxidative stress and/or inflammation may be insufficient to initiate acute pancreatitis.

Topics: Acute Disease; alpha-Amylases; Animals; Ceruletide; Cloning, Molecular; Cytokines; Escherichia coli; Genes, fos; Glutathione; Heme Oxygenase (Decyclizing); Heme Oxygenase-1; Interleukin-1; Interleukin-6; Lipopolysaccharides; Male; Membrane Proteins; Metallothionein; Mice; Mice, Inbred Strains; Oxidative Stress; Pancreas; Pancreatitis; Proto-Oncogene Proteins c-fos; RNA, Messenger; Transcription, Genetic; Tumor Necrosis Factor-alpha

Recent findings have suggested that oxygen-derived free radicals play an important role in the development and progression of acute pancreatitis. Therefore, the present study was designed to investigate whether metallothionein, a free radical scavenger, can protect against acute pancreatitis. Rats were injected intraperitoneally with zinc, followed by either an infusion of cerulein at 10 micrograms/kg for 4 h or a retrograde injection with 100 microliters/100 g body weight of 5% sodium taurocholate into the pancreaticobiliary duct, in order to induce acute pancreatitis. Zn administration significantly increased the levels of both metallothionein and reduced glutathione in the pancreas; the metallothionein levels reached a peak of 83-fold of normal levels after 24 h. The indications of acute pancreatitis, as well as the mortality, were improved by Zn treatment before the onset of acute pancreatitis. Immunohistochemical studies showed that metallothionein accumulated in the acini of the pancreas in the Zn-treated groups, and with strong staining around the periphery of the vacuoles in the group treated with both Zn and cerulein. These findings suggested that Zn increased both metallothionein and glutathione levels in the pancreas and exerted a beneficial effect against ceruleinor taurocholate-induced acute pancreatitis in rats.

Topics: Acute Disease; Animals; Ceruletide; Free Radical Scavengers; Free Radicals; Glutathione; Immunohistochemistry; Male; Metallothionein; Pancreas; Pancreatitis; Rats; Rats, Wistar; Taurocholic Acid; Thiobarbituric Acid Reactive Substances; Zinc

Copper (Cu) accumulating bound to metallothionein (MT) in the liver of LEC (Long-Evans with cinnamon-like coat color) rats due to a hereditary metabolic disorder is assumed to lead to acute hepatitis with severe jaundice. The metal was shown to be present in the liver in a form not bound to MT at the beginning of hepatitis after first delivery and lactation. Following this change in the distribution of Cu from MT-bound to non-MT bound form in the liver, changes in the concentrations and distributions of Cu, zinc (Zn) and iron in the plasma and kidneys of LEC rats were also observed. Cu plasma distribution on a gel filtration column by HPLC-ICP revealed that the holo-form of ceruloplasmin (Cp) was present before hepatitis and increased with its development, indicating the availability of Cu for Cp by hepatitis. Cu-binding proteins migrating at the same retention times as those of hepatic Cu-MT and Cu,Zn-superoxide dismutase (SOD) were detected in plasma during hepatitis. Albumin was largely present in the form of nonmercaptoalbumin, reflecting that the bloodstream was under oxidative stress. A sudden increase in the concentration of Cu in the kidneys occurred with hepatitis, and the metal came to be distributed more to high molecular weight proteins with its development.

Topics: Acute Disease; Animals; Copper; Female; Hepatitis, Animal; Iron; Kidney; Metallothionein; Rats; Rats, Inbred Strains; Sulfur; Zinc

Rats subjected to chronic immobilization stress showed a reduced serum metallothionein (MT) response to acute immobilization stress compared to nonchronically stressed rats. In contrast, liver MT response to acute immobilization stress was not influenced by previous chronic immobilization stress. These results suggest that serum MT levels are likely under endocrine regulation and that they do not reflect directly liver MT levels. Instead it appears that both MT pools are regulated differently. The fact that liver MT is resistant to adaptation to chronic stress may be related to its physiological function.

Topics: Acute Disease; Animals; Chronic Disease; Liver; Male; Metallothionein; Rats; Rats, Sprague-Dawley; Stress, Physiological

Prepuberal and adult male rats were chronically stressed for a month with several acute stressors in a random schedule. Some of the animals were killed approximately 20 hours after the last stress session without any additional stress. Other animals from both control and chronic stress groups were subjected to an acute restraint stress for 15 min before being killed. While chronic stress did not alter hepatic metallothionein (MT) either in prepuberal or in adult rats, this treatment significantly increased serum MT levels in young but not in adult rats. Likewise, 15 min of restraint stress increased serum MT levels in young rats only, regardless of whether they were control or chronically stressed rats. The present data indicate that acute and chronic stressors may alter serum MT in an age-dependent fashion.

Topics: Acute Disease; Aging; Animals; Chronic Disease; Male; Metallothionein; Rats; Rats, Inbred Strains; Stress, Physiological

Three groups of rats (B-D) were given various daily doses of CdCl2 (0.5-2 mg Cd/kg) continuously or in intervals during time periods of 1-8 weeks. Another group of animals (A) were kept untreated. At the end of the period, selected subgroups of groups A-D were given a single subcutaneous injection of 109Cd-metallothionein (109CdMT) 0.05 or 0.4 mg Cd/kg ("challenge dose"). Subsequently, urinary creatinine, protein, Cd, 109Cd and MT and kidney cortex Cd, 109Cd and MT were determined. In group A (no long term pretreatment), an increased proteinuria was observed after the rats had received the lower of the challenge doses of 109CdMT, and an even greater increase after the higher challenge dose of 109CdMT. No such increase appeared in group B, C and D (repeatedly pretreated with CdCl2) at either of the challenge doses. Higher metallothionein concentrations in kidney cortex observed in the pretreated groups constitute a plausible explanation of the protective effects of pretreatment against the development of increased proteinuria after challenge dosing. It is likely that increasing Cd concentrations, gradually accumulating in the renal cortex (22-226 micrograms/g wet wt.) as a result of the pretreatment, served to induce the synthesis of metallothionein in the renal cortical cells, thus making them resistant to the challenge from 109CdMT.

Topics: Acute Disease; Animals; Cadmium; Cadmium Chloride; Kidney Diseases; Male; Metallothionein; Proteinuria; Rats

Topics: Acute Disease; Animals; Cadmium; Cadmium Poisoning; Chelating Agents; Edetic Acid; Liver; Male; Metallothionein; Mice; Mice, Inbred Strains; Pentetic Acid; Succimer; Time Factors