Search results for "wistar"
showing 10 items of 1094 documents
Cannabinoid type 1 receptor modulates intestinal propulsion by an attenuation of intestinal motor responses within the myenteric part of the peristal…
2007
Cannabinoid-1 (CB1) receptor activation affects gastrointestinal propulsion in vivo. It was our aim to further characterize the involved myenteric mechanisms in vivo and in vitro. In CB1(-/-) mice and wild-type littermates we performed in vivo transit experiments by charcoal feeding and in vitro electrophysiological recordings in mouse small intestinal smooth muscle. Ascending neuronal contraction (ANC) following electrical field stimulation was studied in rat ileum in a partitioned organ bath separating the aboral stimulation site from the oral recording site. The knockout animals displayed an accelerated upper gastrointestinal transit compared to control animals. The CB1 receptor antagoni…
Influence of gamma-aminobutyric acid on baclofen intestinal absorption.
1994
Since previous studies suggested that baclofen absorption in the rat middle intestine was inhibited by beta-alanine and therefore mediated, at least in part, by the beta-aminoacid carrier, we focused our new studies on the analysis of the possible inhibition of the drug by a gamma-aminoacid model compound, gamma-aminobutyric acid (GABA). A rat jejunum in situ study was undertaken in order to evaluate the effect of GABA on baclofen absorption and to establish the inhibition model. Assays using isotonic perfusion solutions of 0.5 mM baclofen with starting GABA concentrations ranging from 0 to 100 mM are reported. The results show that the absorption rate pseudoconstants of the drug decrease a…
Digestion and absorption rates of [3H]-oleic acid and [14C]-triolein do not differ in rats fed heated (-) and (+) gossypol cottonseed and soybean flo…
1998
This study was conducted to compare in vivo the acute effects of heated (+) and (-) gossypol cottonseed flours with those of soybean flour on lipid digestion and absorption in growing rats. Rats were fed by gastric intubation mixed [ 3 H]-oleic acid and [ 14 C]-triolein with heated flours or without flour (control). Lipid digestion and absorption were determined for 6 h after meal intubation. Both radioactivities recovered in gastrointestinal tract were significantly higher in rats fed (+) gossypol cottonseed flour than in all other groups. The majority of both recovered radioactivities was found in stomach contents, then in stomach wall and finally in intestinal wall. The distribution of b…
Intestinal absorption pathway of gamma-aminobutyric acid in rat small intestine.
1994
Intestinal absorption of gamma-aminobutyric acid (GABA), as a model compound for gamma-aminoacids, has not been extensively studied from the kinetic viewpoint. Since data from our laboratory suggested that some competition arises between intestinal absorption of beta-alanine and GABA and since our intent was to maintain the aqueous stagnant diffusion layer in order to approach absorption tests to in vivo physiological conditions, a rat jejunum in situ study was undertaken in order to gain an insight into the mechanism of GABA absorption. In the present paper, results from assays using isotonic perfusion solutions with starting GABA concentrations ranging from 1 to 50 mM are reported. They s…
Physiological and metabolic actions of mycophenolate mofetil on cultured newborn rat cardiomyocytes in normoxia and in simulated ischemia
2004
Mycophenolate mofetil (MMF) is a new immunosuppressive drug used to reduce acute rejection after heart transplantation. As with other immunosuppressive drugs, MMF therapy is associated with several adverse effects. However, the direct effects of MMF on myocardial tissue has not been yet evaluated. The aim of the work was thus to evaluate the effects of MMF on isolated cardiomyocytes (CM) in normal conditions and in an in vitro model of simulated ischemia (SI; substrate-free hypoxia) and reperfusion (R; reoxygenation). Myocyte-enriched cultures were prepared from newborn rat heart ventricles. The transmembrane potentials were recorded using conventional microelectrodes and the cell contracti…
Comparison of diffusion, cytotoxicity and tissue inflammatory reactions of four commercial bleaching products against human dental pulp stem cells
2018
AbstractMultiple side effects related to bleaching were found to occur in the dental pulp tissue, including decreased cell metabolism and viability. In this work we evaluated the in vitro diffusion capacity, cytotoxicity and biocompatibility of four commercial bleaching products on stem cells from human dental pulp (hDPSCs). Two commercial bleaching gels hydrogen peroxide-based (HP), Norblanc Office 37.5% (Nor-HP) and Opalescence Boost 40% (Opal-HP) were applied for 30 min to enamel/dentine discs. Another two gels from the same manufacturers, 16% carbamide peroxide-based (CP), Norblanc Home (Nor-CP) and Opalescence CP 16% (Opal-CP), were applied for 90 min. The diffusion of HP was analysed …
Urea cycle dysregulation in non-alcoholic fatty liver disease.
2018
Background & Aims: In non-alcoholic steatohepatitis (NASH), the function of urea cycle enzymes (UCEs) may be affected, resulting in hyperammonemia and the risk of disease progression. We aimed to determine whether the expression and function of UCEs are altered in an animal model of NASH and in patients with non-alcoholic fatty liver disease (NAFLD), and whether this process is reversible. Methods: Rats were first fed a high-fat, high-cholesterol diet for 10 months to induce NASH, before being switched onto a normal chow diet to recover. In humans, we obtained liver biopsies from 20 patients with steatosis and 15 with NASH. Primary rat hepatocytes were isolated and cultured with free fatty …
Effect of Age and Lipoperoxidation in Rat and Human Adipose Tissue-Derived Stem Cells
2020
A wide range of clinical applications in regenerative medicine were opened decades ago with the discovery of adult stem cells. Highly promising adult stem cells are mesenchymal stem/stromal cells derived from adipose tissue (ADSCs), primarily because of their abundance and accessibility. These cells have multipotent properties and have been used extensively to carry out autologous transplants. However, the biology of these cells is not entirely understood. Among other factors, the regeneration capacity of these cells will depend on both their capacity of proliferation/differentiation and the robustness of the biochemical pathways that allow them to survive under adverse conditions like thos…
Uncoupling protein-2 (UCP2) induces mitochondrial proton leak and increases susceptibility of non-alcoholic steatohepatitis (NASH) liver to ischaemia…
2008
Background: The mechanisms of progression from fatty liver to steatohepatitis and cirrhosis are not well elucidated. Mitochondrial dysfunction represents a key factor in the progression of non-alcoholic steatohepatitis (NASH) as mitochondria are the main cellular site of fatty acid oxidation, ATP synthesis and reactive oxygen species (ROS) production. Aims: (1) To evaluate the role of the uncoupling protein 2 in controlling mitochondrial proton leak and ROS production in NASH rats and humans; and (2) to assess the acute liver damage induced by ischaemia–reperfusion in rats with NASH. Methods: Mitochondria were extracted from the livers of NASH humans and rats fed a methionine and choline de…
Mechanism of Free Radical Production in Exhaustive Exercise in Humans and Rats; Role of Xanthine Oxidase and Protection by Allopurinol
2000
Exhaustive exercise generates free radicals, However, the source of this oxidative damage remains controversial. The aim of this paper was to study further the mechanism of exercise-induced production of free radicals, Testing the hypothesis that xanthine oxidase contributes to the production of free radicals during exercise, me found not only that exercise caused an increase in blood xanthine oxidase activity in rats but also that inhibiting xanthine oxidase with allopurinol prevented exercise-induced oxidation of glutathione in both rats and in humans. Furthermore, inhibiting xanthine oxidase prevented the increases in the plasma activity of cytosolic enzymes (lactate dehydrogenase, aspar…