Search results for "wistar"
showing 10 items of 1094 documents
Differential effects of diabetes on the expression of the gp91phox homologues nox1 and nox4.
2004
The nox2-dependent NADPH oxidase was shown to be a major superoxide source in vascular disease, including diabetes. Smooth muscle cells of large arteries lack the phagocytic gp91phox subunit of the enzyme; however, two homologues have been identified in these cells, nox1 and nox4. It remained to be established whether also increases in protein levels of the nonphagocytic NADPH oxidase contribute to increased superoxide formation in diabetic vessels. To investigate changes in the expression of these homologues, we measured their expression in aortic vessels of type I diabetic rats. Eight weeks after streptozotocin treatment, we found a doubling in nox1 protein expression, while the expressio…
Actions of alpha-adrenoceptor blocking agents on two types of intracellular calcium stores mobilized by noradrenaline in rat aorta.
1993
In isolated rat aortic strips noradrenaline induces a biphasic contractile response in Ca-free medium, associated with two different intracellular calcium pools, one of which is common to caffeine. We analyzed the mechanisms involved in the depletion and repletion of both intracellular Ca pools sensitive to noradrenaline in different experimental procedures in presence of prazosin, phentolamine and yohimbine. At 37 degrees C the alpha-adrenergic blocking agents inhibited contractile responses to noradrenaline in Ca-free medium, with prazosin being highly selective. alpha 2-adrenoceptors probably do not participate in the release of Ca from internal stores, as no contractile response was obs…
Calcium and increase excitability promote tolerance against anoxia in hippocampal slices.
1999
We have previously demonstrated that anoxic preconditioning (APC) protects against a subsequent otherwise 'lethal' anoxic insult in hippocampal slices. Tested here are two hypotheses: (a) APC requires calcium to improve electrical recovery in hippocampal slices; and (b) mild excitation promotes preconditioning neuroprotection. Control hippocampal slices were given a single 'test' anoxic insult followed by reoxygenation. Experimental slices were preconditioned by three short anoxic insults of 1 min separated by 10 min of reoxygenation. At 30 min after the third 'conditioning' insult, slices underwent a 'test' anoxic insult [1 min of anoxic depolarization (AD)], and then slices were reoxygena…
Release of choline from rat brain under hypoxia: contribution from phospholipase A2 but not from phospholipase D
1993
Moderate hypoxia induced in rats by inhalation of 10% oxygen led to an increase of the concentration of free choline in the brain and caused a large net-release of choline from the brain into the venous blood as determined by the measurement of the arterio-venous difference. In hippocampal slices from rat brain, hypoxia increased the release of choline into the superfusion medium. The activity of phospholipase D, as measured by the formation of phosphatidylpropanol in the presence of propanol, was not stimulated under these conditions. However, the mobilization of choline was completely depressed by lowering extracellular calcium and by 0.1 mM mepacrine. We conclude that hypoxia leads to a …
Structural analysis of rat patellar tendon in response resistance and endurance training.
2009
Little is known about tendon adaptations induced by mechanical loading. Our goal was to evaluate the effects of two different exercise training protocols on adult rat patellar tendon. Ninety-six male Wistar rats were divided into a sedentary group (control), a resistance-trained group and an endurance-trained group. The examinations were performed after 15, 30 and 45 days of training and after 2 weeks of rest since training was stopped. The content of collagen fibers and the cell nuclei number were quantified on tendon cross sections. In order to assess the training effectiveness, we evaluated the heart/body weight ratio, which was higher in 45 day-trained rats than their controls (P<0.01),…
Portulaca oleracea reduces triglyceridemia, cholesterolemia, and improves lecithin: cholesterol acyltransferase activity in rats fed enriched-cholest…
2014
Abstract Purpose The effects of Portulaca oleracea ( Po ) lyophilized aqueous extract were determined on the serum high-density lipoproteins (HDL 2 and HDL 3 ) amounts and composition, as well as on lecithin: cholesterol acyltansferase (LCAT) activity. Methods Male Wistar rats ( n = 12) were fed on 1% cholesterol-enriched diet for 10 days. After this phase, hypercholesterolemic rats (HC) were divided into two groups fed the same diet supplemented or not with Portulaca oleracea ( Po -HC) (0.5%) for four weeks. Results Serum total cholesterol (TC) and triacylglycerols (TG), and liver TG values were respectively 1.6-, 1.8-, and 1.6-fold lower in Po -HC than in HC group. Cholesterol concentrat…
Enhancement of activities relative to fatty acid oxidation in the liver of rats depleted of l-carnitine by d-carnitine and a γ-butyrobetaine hydroxyl…
1995
Abstract This study was designed to examine whether the depletion of l -carnitine may induce compensatory mechanisms allowing higher fatty acid oxidative activities in liver, particularly with regard to mitochondrial carnitine palmitoyltransferase I activity and peroxisomal fatty acid oxidation. Wistar rats received d -carnitine for 2 days and 3-(2,2,2-trimethylhydrazinium)propionate (mildronate), a non-competitive inhibitor of γ-butyrobetaine hydroxylase, for 10 days. They were starved for 20 hr before being sacrificed. A dramatic reduction in carnitine concentration was observed in heart, skeletal muscles and kidneys, and to a lesser extent, in liver. Triacylglycerol content was found to …
Effects of endotoxin on neurally-mediated gastric acid secretion in the rat.
1998
Abstract The effects of a peripheral administration of E. coli endotoxin on neurally-mediated gastric acid secretion and the role of endogenous opioids or PAF receptors in endotoxin effects have been evaluated in the continuously perfused stomach of the anaesthetized rat. Gastric acid secretion stimulated by distension (20 cm H2O) was reduced dose-dependently by single intravenous bolus injection of endotoxin (0.1–10 μg kg−1). Doses of 5 μg kg−1 induced a peak reduction of distension-stimulated acid output and significantly reduced the secretory response induced by an intravenous bolus of 2-deoxy-d-glucose (150 mg kg−1). This dose of endotoxin did not significantly modify mean systemic arte…
Differences in the composition of inflammatory cell infiltrate in lens-induced uveitis under therapy with allopurinol or steroids.
2001
Purpose The aim of this study was to compare the qualitative changes in the composition of inflammatory cell infiltrate in lens-induced uveitis (LIU) under treatment with allopurinol (Allo), methylprednisolone (Pred) or the two drugs combined (Allo/Pred). Methods Twenty male Wistar rats were sensitized with lens proteins for eight weeks. Intravenous (IV) therapy was started after anterior capsule disruption in one eye of each animal. Five rats were randomly assigned to each of the four groups: controls, Allo (50 mg/kg bw), Pred (7.5 mg/kg bw) and Allo/Pred (50 mg/7.5 mg per kg bw). Eyes were enucleated 24 hours later and fixed in paraformaldehyde/glutaraldehyde. Sections at three levels wer…
Nitric Oxide Modulates the Acute Increase of Gastrointestinal Transit Induced by Endotoxin in Rats: a Possible Role for Tachykinins
1997
Abstract Because of the evidence that endogenous nitric oxide (NO) plays an essential role in the physiological regulation of gastrointestinal motility we have investigated, by use of the NO synthase inhibitor, NG-nitro-l-arginine methyl ester (l-NAME), the role of endogenous NO in the acute endotoxin-induced changes of gastrointestinal transit. Pre-treatment with E. coli endotoxin (100 μg kg−, i.v.) induced a significant increase in the gastrointestinal transit of a charcoal suspension in anaesthetized rats. Previous administration of the NO synthase inhibitor, l-NAME (10 mg kg−, i.v.) significantly prevented the effects of endotoxin. l-arginine (200 mg kg−, i.v.) and the substance P antag…