Search results for "wistar"
showing 10 items of 1094 documents
β-Adrenoceptors differentially regulate vascular tone and angiogenesis of rat aorta via ERK1/2 and p38
2014
β-Adrenoceptors (β-ARs) modulate ERK1/2 and p38 in different cells, but little is known about the contribution of these signaling pathways to the function of β-ARs in vascular tissue. Immunoblotting analysis of rat aortic rings, primary endothelial (ECs) and smooth muscle cells (SMCs) isolated from aorta showed that β-AR stimulation with isoprenaline activated p38 in aortic rings and in both cultured cell types, whereas it had a dual effect on ERK1/2 phosphorylation, decreasing it in ECs while increasing it in SMCs. These effects were reversed by propranolol, which by itself increased p-ERK1/2 in ECs. Isoprenaline β-AR mediated vasodilation of aortic rings was potentiated by the ERK1/2 inhi…
The influence of active secretion processes on intestinal absorption of salbutamol in the rat.
2001
Abstract Salbutamol was perfused in the small intestine of rat using a standard rat gut ‘in situ’ preparation: (1) in inhibitor-free solution at seven different concentrations (0.15, 0.29, 1.20, 5.0, 9.0, 13.0 and 18.0 mM); (2) at a 0.29 mM concentration – thought to be close to the allometric dose in man – in the presence of a non-specific enzyme inhibitor, sodium azide (0.3, 3.0 and 6.0 mM); and (3) at 0.29 mM in the presence of a selective secretion inhibitor, verapamil (10.0 and 20.0 mM). In free solution, the mixed-order rate constants, k ′ a , of salbutamol increase as the solute concentration increases until an apparent asymptotic value is reached. This could be due to the saturation…
Changes in lipid metabolism and antioxidant defense status in spontaneously hypertensive rats and Wistar rats fed a diet enriched with fructose and s…
2005
Abstract Objective Larger doses of fructose and saturated fat have been associated with oxidative stress and development of hypertension. The effects of modest amounts of fructose and saturated fatty acids on oxidative stress are unknown. Methods To increase knowledge on this question, 10-wk-old spontaneously hypertensive rats and Wistar rats were fed for 8 wk with a control diet or an experimental diet enriched with fructose (18%) and saturated fatty acids (11%; FS diet). The total antioxidant status of organs and red blood cells was assayed by monitoring the rate of free radical-induced red blood cell hemolysis. Sensitivity of very low-density lipoprotein and low-density lipoprotein (VLDL…
Risk of gallstone disease in advanced chronic phase of fascioliasis: an experimental study in a rat model.
2003
In Wistar rats experimentally infected with Fasciola hepatica, the association between time of infection, number of flukes, rat weight, and serum lipid levels and the risk of developing pigment stones in the main bile duct was examined using data obtained at 100, 200, 300, 400, and 500 days postinfection. Gallstone presence increased with infection time. The relative risk of gallstone disease increased when the number of flukes per rat and rat weight increased. The presence of gallstones was associated with serum high-density lipoproteins and triglyceride levels. In a multivariate analysis, the association between gallstones and rat weight disappeared after adjustment for serum lipids. The …
Low-protein diet prevents tissue lipoprotein lipase activity increase in growing rats
2000
The time course of changes in tissue lipolytic activities was studied in young rats during theconsumption of a low-protein diet containing 50 g protein/kg (40 g wheat gluten +10 g casein/kg) for 28 d followed by balanced refeeding with 200 g protein/kg (160 g wheat gluten +40 gcasein/kg) for 28 d. Lipoprotein lipase (LPL) activities were compared with the values of acontrol group fed a balanced diet containing 200 g protein/kg for 56 d. At the end of proteinmalnutrition period, the epididymal fat tissue LPL activity represented 36 %, and that of heartand gastrocnemius was 44 %, of those of the control group. These differences wereaccompanied by lower serum- and VLDL-triacylglycerols (TAG), …
Carnitine congener mildronate protects against stress- and haloperidol-induced impairment in memory and brain protein expression in rats.
2014
The present study investigates the efficacy of mildronate, a carnitine congener, to protect stress and haloperidol-induced impairment of memory in rats and the expression of brain protein biomarkers involved in synaptic plasticity, such as brain-derived neurotrophic factor (BDNF), acetylcholine esterase and glutamate decarboxylase 67 (GAD67). Two amnesia models were used: 2h immobilization stress and 3-week haloperidol treatment. Stress caused memory impairment in the passive avoidance test and induced a significant 2-fold BDNF elevation in hippocampal and striatal tissues that was completely inhibited by mildronate. Mildronate decreased the level of GAD67 (but not acetylcholine esterase) e…
Liver intracellular L-cysteine concentration is maintained after inhibition of the trans-sulfuration pathway by propargylglycine in rats.
1997
To study the fate ofl-cysteine and amino acid homeostasis in liver after the inhibition of the trans-sulfuration pathway, rats were treated with propargylglycine (PPG). At 4 h after the administration of PPG, liver cystathionase (EC4.4.1.1) activity was undetectable,l-cystathionine levels were significantly higher,l-cysteine was unchanged and GSH concentration was significantly lower than values found in livers from control rats injected intraperitoneally with 0.15 M-NaCl. The hepatic levels of amino acids that are intermediates of the urea cycle,l-ornithine,l-citrulline andl-arginine and blood urea were significantly greater. Urea excretion was also higher in PPG-treated rats when compared…
Effects of sulpiride on the orienting movement evoked By acoustic stimulation in the Rat.
2000
Abstract Drugs that selectively block D 2 receptors are known to provoke a rapid cell firing increase followed by A9 and A10 dopaminergic (DA) neuron inactivation (depolarization block). In this study, possible relationships between cell firing rapid increase and specific behavioral effects, linked to sensorimotor integration, were investigated in the rat. To this purpose, with the aid of a video camera apparatus and a frame-by-frame analysis, effects of sulpiride-induced blockade of DA D 2 receptors were analyzed on the orienting movement of the head induced by acoustic stimulation. In a control group of rats, during trials lasting 20 min, latency and duration of head turning (HT) were 186…
An experimental comparative study of dexamethasone, melatonin and tacrolimus in noise-induced hearing loss.
2008
The calcineurin inhibitor tacrolimus (TCR) and the pineal gland hormone and antioxidant melatonin (MLT) have been shown to possess otoprotective properties against noise-induced hearing loss (NIHL). In contrast, dexamethasone (DXM) was not effective as an otoprotective agent against NIHL. Further studies are needed to understand the exact molecular mechanisms involved.Exposure to noise pollution and use of audio devices for long periods of time at high volume is known to cause hearing loss or NIHL. Our goal was to evaluate the effectiveness of various known compounds such as the anti-inflammatory DXM, the antioxidant MLT and the immunosuppressant TCR against NIHL.Thirty-two Wistar rats were…
Nitric oxide and glutamate interaction in the control of cortical and hippocampal excitability.
1999
Summary: Purpose: We investigated the role of nitric oxide (NO) as a new neurotransmitter in the control of excitability of the hippocampus and the cerebral cortex, as well as the possible functional interaction between NO and the glutamate systems. Methods: The experiments were performed on anesthetized rats. The bioelectrical activities of the somatosensory cortex and the CA1 region of the hippocampus of these rats were recorded. Pharmacologic inhibition of NO synthase (NOS) through the nonselective and brain-selective inhibitors, N-nitro-L-arginine methyl ester (l-NAME) and 7-nitroindazole (7-NI), was performed. Results: The treatments caused the appearance of an interictal discharge act…