0000000000423937
AUTHOR
Josep M. Piqué
Acute normovolaemic anaemia prevents ethanol-induced gastric damage in rats through a blood flow related mechanism.
The aim of the study was to assess whether changes in gastric mucosal blood flow induced by acute normovolaemic anaemia influence the susceptibility of the gastric mucosa to ethanol-induced damage, and the relationship of these changes with nitric oxide biosynthesis. Acute normovolaemic anaemia, promoted by exchanging 3 ml of blood by a plasma expander, induced a significant increase in gastric mucosal blood flow measured by hydrogen gas clearance, without changes in arterial blood pressure. After intragastric 60% ethanol administration, gastric blood flow was still significantly higher in anaemic than in control rats, and this was associated with a lower macroscopic and microscopic gastric…
NEONATAL CAPSAICIN TREATMENT DOES NOT PREVENT SPLANCHNIC VASODILATATION IN PORTAL-HYPERTENSIVE RATS
It has been suggested that the peripheral sensory neurons are involved in the splanchnic hemodynamic changes of portal hypertension. Therefore the influence of permanent ablation of sensory neurons by neonatal capsaicin pretreatment (50 mg/kg, subcutaneously) on the development of the hyperdynamic splanchnic circulation in portal-hypertensive rats was studied. In adulthood, portal hypertension was induced with partial portal vein ligation. In study 1, systemic and splanchnic hemodynamics were measured by means of a radiolabeled-microsphere technique in portal-hypertensive rats, under ketamine anesthesia, pretreated with capsaicin or vehicle. Mean arterial pressure, heart rate, cardiac index…
Replenishment of glutathione levels improves mucosal function in experimental acute colitis.
Because reactive oxygen species (ROS) have been implicated as mediators of inflammatory bowel disease (IBD), the purpose of the present work was to determine the functional role of mucosal GSH in the trinitrobenzenesulfonic acid in 50% ethanol (TNBS+ethanol)-induced colitis in rats. Mucosal samples were taken to evaluate the temporal relationship between the extent of injury, the levels of glutathione (GSH) during acute colitis induced by TNBS+ethanol, and the effect of N-acetylcysteine (NAC) administration. In vitro assays revealed the interaction of TNBS with GSH leading to the almost instantaneous disappearance of GSH, while the reductive metabolism of TNBS by GSSG reductase generated RO…
Nitric oxide mediates the inhibition by interleukin-1β of pentagastrin-stimulated rat gastric acid secretion
Bolus injection of interleukin-1 beta (2 micrograms kg-1, i.v.) inhibited acid secretion induced by intravenous infusion of pentagastrin (8 micrograms kg-1 h-1) in the continuously perfused stomach of the anaesthetized rat. Administration of interleukin-1 beta did not modify mean systemic arterial blood pressure. Pretreatment with NG-nitro-L-arginine methyl ester (L-NAME, 2-10 mg kg-1, i.v.), but not dexamethasone (5 mg kg-1, s.c. twice over 16 h), restored the acid secretory responses to pentagastrin. The actions of L-NAME were reversed by the prior administration of L-arginine (100 mg kg-1, i.v.), but not by its enantiomer D-arginine (100 mg kg-1, i.v.). L-NAME (5 mg kg-1, i.v.) increased…