apyrase and Body-Weight

Caffeine or ketorolac decrease the risk of retinopathy of prematurity and may act synergistically to improve beneficial effect. Combination of caffeine (Caff) and ketorolac (Keto) to prevent oxygen-induced retinopathy was studied.. Newborn rats exposed to room air (RA) or intermittent hypoxia (IH) consisting of 12% O2 during hyperoxia (50% O2) from birth (P0) had single daily IP injections of Caff from P0-P13 or saline; and/or ocular Keto (Acuvail, 0.45% ophthalmic solution) administered subcutaneously over the eyes from P5-P7. Pups were studied at P14 or placed in RA for recovery from IH (IHR) until P21. Eyes were examined for neovascularization, histopathology, growth factors, and VEGF-signaling genes.. Severe retinal damage noted during IHR in the untreated groups evidenced by hemorrhage, neovascularization, and oxygen-induced retinopathy (OIR) pathologies were prevented with Keto/Caff treatment. Keto and/or Caff treatment in IH also promoted retinal neural development evidenced by eye opening (92%, P < 0.001 vs. 31% in the placebo-treated IH group). No corneal pathologies were noted with Keto.. Caff or Keto given individually reduced retinal neovascularization, but the two drugs given together prevented severe OIR.

Topics: Animals; Animals, Newborn; Anti-Inflammatory Agents, Non-Steroidal; Apyrase; Arteries; Body Weight; Caffeine; Central Nervous System Stimulants; Choroid; Citrates; Dinoprost; Drug Synergism; Female; Hemorrhage; Hypoxia-Inducible Factor 1, alpha Subunit; Insulin-Like Growth Factor I; Intercellular Signaling Peptides and Proteins; Ketorolac; Neovascularization, Pathologic; Oxygen; Rats; Rats, Sprague-Dawley; Retina; Retinopathy of Prematurity; Signal Transduction; Time Factors; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factor Receptor-1

Although the etiology of two major forms of inflammatory bowel disease (IBD), Crohn's disease (CD) and ulcerative colitis (UC) are unknown and evidence suggests that chronic intestinal inflammation is caused by an excessive immune response to mucosal antigens. Previous studies support the role for TGF-β1 through 3 in the initiation and maintenance of tolerance via the induction of regulatory T cells (Tregs) to control intestinal inflammation. Leptin, a satiety hormone produced primarily by adipose tissue, has been shown to increase during colitis progression and is believed to contribute to disease genesis and/or progression.. We investigated the ability of a pegylated leptin antagonist (PG-MLA) to ameliorate the development of chronic experimental colitis.. Compared to vehicle control animals, PG-MLA treatment of mice resulted in an (1) attenuated clinical score; (2) reversed colitis-associated pathogenesis including a decrease in body weight; (3) reduced systemic and mucosal inflammatory cytokine expression; (4) increased insulin levels and (5) enhanced systemic and mucosal Tregs and CD39⁺ Tregs in mice with chronic colitis. The percentage of systemic and mucosal TGF-β1, -β2 and -β3 expressing CD4⁺ T cells were augmented after PG-MLA treatment. The activation of STAT1 and STAT3 and the expression of Smad7 were also reduced after PG-MLA treatment in the colitic mice. These findings clearly suggest that PG-MLA treatment reduces intestinal Smad7 expression, restores TGF-β1-3 signaling and reduces STAT1/STAT3 activation that may increase the number of Tregs to ameliorate chronic colitis.. This study clearly links inflammation with the metabolic hormone leptin suggesting that nutritional status influences immune tolerance through the induction of functional Tregs. Inhibiting leptin activity through PG-MLA might provide a new and novel therapeutic strategy for the treatment of IBD.

Topics: Animals; Antigens, CD; Apyrase; Body Weight; Chronic Disease; Colitis; Down-Regulation; Female; Insulin; Interleukin-10; Intestinal Mucosa; Leptin; Mice; Mice, Inbred C57BL; Mice, Knockout; Polyethylene Glycols; Recombinant Proteins; Signal Transduction; Smad7 Protein; STAT1 Transcription Factor; STAT3 Transcription Factor; T-Lymphocytes, Regulatory; Transforming Growth Factor beta

n-3 polyunsaturated fatty acids (PUFAs) modify T-cell activation, in part by remodeling lipid composition; however, the relationship between n-3 PUFA and B-cell activation is unknown. Here we tested this relationship in vitro and ex vivo by measuring upregulation of B-cell surface molecules, the percentage of cells activated, and cytokine secreted in response to lipopolysaccharide (LPS) activation. In vitro, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) improved the membrane n-6/n-3 PUFA ratio, and DHA lowered interleukin (IL)-6 secretion; overall, n-3 PUFAs did not suppress B-cell activation compared with BSA, oleate, or elaidate treatment. Palmitate treatment suppressed the percentage of B cells activated through lipoapoptosis, which was differentially prevented by cosupplementing cells with MUFAs and PUFAs. Ex vivo, we tested the hypothesis with mice fed a control or high-fat saturated, hydrogenated, MUFA or n-3 PUFA diets. n-3 PUFAs had no effect on the percentage of B cells activated. Unexpectedly, the n-3 PUFA diet increased B-cell CD69 surface expression, IL-6 and IFNgamma secretion, and it significantly increased body weight gain. Overall, we propose that changes in lipid composition with n-3 PUFA and suppression of lymphocyte activation is not universal. The study highlights that high-fat n-3 PUFA diets can promote pro-inflammatory responses, at least from one cell type.

Topics: Animals; Antigens, CD; Apoptosis; Apyrase; B-Lymphocytes; Body Weight; Cytokines; Dietary Fats; Fatty Acids; Fatty Acids, Monounsaturated; Fatty Acids, Omega-3; Male; Mice; Mice, Inbred C57BL; Organ Size; Palmitates; Spleen; Time Factors; Up-Regulation

The vascular changes associated with early diabetic retinopathy, which include the formation of microaneurysms and acellular capillaries, vessel dilation, vascular endothelial growth factor expression, were investigated experimentally in streptozotocin-induced diabetic rats treated with antioxidants: troxerutin (trihydroxy-ethylrutoside, CAS 7085-55-4), Vaccinium myrtillus, and calcium dobesilate (hydroquinone calcium sulfonate, CAS 20123-80-2). The development and progression of retinopathy was followed using fundus photography. After 3 months, the rats were sacrificed and half of the eyes were prepared for neovascularization analysis, and the other half were used for VEGF (vascular endothelial growth factor) analysis. The results from fundus photography and ADPase (adenosine diphosphatase) staining were quantified by the percentage area of the retinal vasculature using a commercial image analyzer. The VEGF protein in the retinal homogenates was assessed using an ELISA (enzyme linked immunosorbent assay) kit and VEGF-mRNA by RT-PCR (reverse transcription polymerase chain reaction). In the ADPase stain, the retinal vascular percent area increased significantly in the diabetic control. Neovascularization and aneurysms were observed in the diabetic control and were attenuated by 50 mg/kg troxerutin, but the retinal vascular percentage area was not significantly different from the diabetic control. The VEGF protein concentration was higher in diabetic rats than in the nondiabetic rats (21.5 +/- 2.1 vs 27.7 +/- 5.8 pg/mg, p < 0.05), and this increase was attenuated by 10 mg/kg troxerutin (24.5 +/- 3.8 pg/mg, p < 0.05) and prevented by 50 mg/kg troxerutin (19.5 +/- 2.2 pg/mg, p < 0.05). However, there were no significant differences between the groups. The VEGF-mRNA density showed a increasing tendency by 20% in the diabetic rats compared with the non-diabetic rats (1.0 +/- 0.1 vs 1.2 +/- 0.1 VEGF/beta-actin), and this increase was corrected by 10 mg/kg troxerutin (1.0 +/- 0.1 VEGF/beta-actin), 50 mg/kg troxerutin (0.9 +/- 0.1 VEGF/beta-actin) and Vaccinium myrtillus (1.1 +/- 0.1 VEGF/beta-actin). Oxidative stress might be involved in the upregulation of retinal VEGF during early diabetes, and it is likely that troxerutin has comparatively effective antioxidant properties. Therefore, troxerutin might be a useful treatment for attenuating diabetic retinopathy.

Topics: Animals; Apyrase; Blood Glucose; Body Weight; Calcium Dobesilate; Diabetes Mellitus, Experimental; Diabetic Retinopathy; Enzyme-Linked Immunosorbent Assay; Fundus Oculi; Hemostatics; Hydroxyethylrutoside; Phytotherapy; Rats; Reverse Transcriptase Polymerase Chain Reaction; RNA; Vaccinium myrtillus; Vascular Endothelial Growth Factor A; Vasoconstrictor Agents

We have previously described a metabolic acidosis-induced retinopathy in the neonatal rat, similar to retinopathy of prematurity (ROP). We also have reported exacerbation of oxygen-induced retinopathy by postnatal growth retardation, produced by raising newborn rats in 'expanded' litters. In the present study, we investigated the effect of postnatal growth retardation on the incidence and severity of acidosis-induced retinopathy.. 100 newborn Sprague-Dawley rats were randomly assigned to two expanded litters of 25 pups each and five standard control litters of 10 pups each. All rats were gavaged with 10 mM/kg NH(4)Cl twice daily from days two to seven. Following five days of recovery, retinal vasculature was assessed using ADPase staining, light microscopy, and computer-assisted image analysis. The presence of neovascularization (NV), severity of NV (clock hours), and vascularized retinal areas, were evaluated in a masked manner.. NV occurred in 52% of rats in expanded litters versus 18% of rats in standard control litters (p = 0.005). Postnatal growth retardation of pups in expanded litters was confirmed by comparing total body weight of pups raised in expanded and standard control litters (10.8g vs 13.4g on day 8, p < 0.001; 20.8g vs 25.2g on day 13, p = 0.002).. Postnatal growth retardation increases the incidence of acidosis-induced retinopathy in the neonatal rat. Our study provides further evidence that postnatal growth retardation is a risk factor for preretinal neovascularization in immature retinae and is consistent with the clinical observation that the smallest and sickest premature infants are more likely to suffer from ROP.

Topics: Acidosis; Ammonium Chloride; Animals; Animals, Newborn; Apyrase; Blood Gas Analysis; Body Weight; Growth Disorders; Humans; Hydrogen-Ion Concentration; Image Processing, Computer-Assisted; Infant, Newborn; Litter Size; Rats; Rats, Sprague-Dawley; Retinal Neovascularization; Retinal Vessels; Retinopathy of Prematurity; Risk Factors

ATPase-ADPase activities in synaptosomes from cerebral cortex was measured in rats of various ages (0-, 7-, 10-, 14- and 21- and 60-90-days). The activities (nmol Pi/min/mg) increased steadily from birth, reaching maximum values at 21 days of age. The increase was primarily due to increases in Vmax; the Km values are the same from birth until adult age. The developmental profile was similar for ATPase-ADPase activities and acetylcholinesterase from the same fraction. Several specific ATPase inhibitors and Ap5A (P1P5-di(adenosine-5)-pentaphosphate) did not interfere with the hydrolysis of ATP and ADP at all ages studied, suggesting that classical ATPases and adenylate kinase were not involved in the degradation of both nucleotides by synaptosomal fraction in the assay conditions. Other phosphatases were also ruled out. It is conceivable that ATPase-ADPase activities play an important role in neurotransmitter metabolism.

Topics: Adenosine Triphosphatases; Aging; Animals; Animals, Newborn; Apyrase; Body Weight; Brain; Cerebral Cortex; Kinetics; Organ Size; Rats; Rats, Wistar; Synaptosomes

1. Early undernutrition can cause permanent functional changes in the central nervous system. Alterations in enzymes involved in neurotransmitter metabolism have been reported to result from early undernutrition. 2. In a previous study, we demonstrated that undernutrition during suckling decreases ATP and ADP hydrolysis by synaptosomes from cerebral cortex by about 20% of the value found in 20-day-old well-nourished rats (J. B. T. Rocha, C. F. Mello, J. J. F. Sarkis and R. D. Dias, British Journal of Nutrition, 63:273-283, 1990). In the present study, we investigated whether this deficit persists in synaptosomes from cerebral cortex of nutritionally rehabilitated adult rats. 3. Rats were undernourished from birth to 25 days of life by feeding their dams a 7% casein (w/w) diet, while well-nourished offspring were fed by mothers maintained on a 28% casein diet. 4. In contrast to the results previously obtained in young rats, the synaptosomes obtained from the cerebral cortex of early undernourished adult rats hydrolyzed ATP and ADP more efficiently than did those obtained from well-nourished rats. Specific activity (nmol min-1 mg protein-1, mean +/- SD) was 114.9 +/- 9.5 for undernourished rats (N = 8) vs 94.1 +/- 9.5 for well-nourished rats (N = 8) for ATP, and 50.4 +/- 6.1 (N = 8) vs 38.8 +/- 4.5 (N = 8) for ADP. These results suggest that the deficits found in young rats disappear in rehabilitated adult rats.

Topics: Adenosine Diphosphate; Adenosine Triphosphate; Age Factors; Animals; Apyrase; Biomarkers; Body Weight; Brain; Cerebral Cortex; Hydrolysis; Organ Size; Protein-Energy Malnutrition; Rats; Synaptic Transmission; Synaptosomes

The presence of activities that hydrolyse externally added ATP to adenosine in synaptosomal preparations from various sources is well demonstrated. The hydrolysis of ATP to AMP can be mediated either by the concerted action of enzymes or by an ATP-diphosphohydrolase (EC 3.6.1.5; apyrase). Undernutrition during the preweaning period can delay the development of several enzymes involved in the metabolism of neurotransmitters or neuronal function. In young rats, the presence of an apyrase in synaptosomal preparations from cerebral cortex was investigated. The results suggested that the hydrolysis of externally added ATP and ADP can be mediated by a single enzyme. The effects of preweaning undernutrition on the hydrolysis of ATP and ADP were also investigated. In weanling rats, previous undernutrition caused a decrease of about 20% in the hydrolysis of both substrates in synaptosomal fractions.

Topics: Adenosine Diphosphate; Adenosine Triphosphate; Animals; Animals, Suckling; Apyrase; Body Weight; Brain; Calcium-Transporting ATPases; Hydrolysis; Nutrition Disorders; Organ Size; Phosphoric Monoester Hydrolases; Rats; Rats, Inbred Strains; Synaptosomes; Weaning

Aortic medial calcification was investigated in rats in which the progeria-like syndrome (PLS) was evoked by administering dihydrotachysterol. In 35 experimental rats and 15 controls, calcification was studied morphologically by light and electron microscopy, and by enzyme histochemistry. Body weight, food intake and serum calcium levels were also determined. Calcification occurred along and on the elastic lamellae in association with the accumulation of ground substance. In the smooth-muscle cells surrounding the calcified foci, the activities of various lysosomal enzymes increased concomitantly with a tendency toward transformation of smooth-muscle cells to a modified form. From these observations, the role of ground-substance formation by smooth-muscle cells is postulated, and participation in the catabolism of ground substance by the lysosomal enzymes of these cells is suggested. It appears the increased activity of adenosine monophosphatase should be linked to the calcification. The etiology of weight loss, skin manifestations and aortic calcification in PLS rats seems to be different from that in human progeric diseases. Therefore, the PLS rat should not be readily accepted as an animal model for the study of progeric diseases.

Topics: Acid Phosphatase; Adenosine Triphosphatases; Animals; Aorta; Aortic Diseases; Apyrase; Body Weight; Calcinosis; Calcium; Dihydrotachysterol; Female; Glucuronidase; Hexosaminidases; Histocytochemistry; Phosphoric Monoester Hydrolases; Rats; Werner Syndrome