We investigated the gastric response to an ulcerogenic irritant and the change in gastric functions in an experimental rat model of obstructive jaundice, with or without biliary drainage. After biliary obstruction for 14 days, rats with ligated bile duct (BDL) were randomly divided into three groups: BDL group without biliary drainage, BDL followed by choledochoduodenostomy (CD) or a choledochovesical fistula (CVF). The gastric functions were evaluated 2 weeks after the surgery. Gastric damage, induced by orogastric administration of ethanol, was evaluated 30 min later using a lesion index and microscopic scoring was then performed on fixed stomachs. Basal gastric acid secretion was measured by the pyloric ligation method.The lesion index and maximum lesion depth did not differ in the BDL and sham groups, while they were significantly reduced in the CD group. Gastric acid output and secretory volume were reduced in the BDL group compared to the sham group, while these reductions were abolished in the CD group. Afferent denervation with capsaicin further reduced the ulcer index in the later group. Our data suggest that gastric mucosal susceptibility to injury is dependent on the normal flow of bile into the duodenal lumen, which appears to be a requirement for adaptive gastric cytoprotection., A. Cingi, R. Ahiskali, B. K. Oktar, M. A. Gülpinar, C. Yegen, B.Ç. Yegen., and Obsahuje bibliografii
The present study was performed to evaluate the role of neuronal nitric oxide synthase (nNOS)-derived nitric oxide (NO) during the developmental phase of hypertension in transgenic rats harboring the mouse Ren-2 renin gene (TGR). The first aim of the present study was to examine nNOS mRNA expression in the renal cortex and to assess the renal functional responses to intrarenal nNOS inhibition by S-methyl-L-thiocitrulline (L-SMTC) in heterozygous TGR and in age-matched transgene-negative Hannover Sprague-Dawley rats (HanSD). The second aim was to evaluate the role of the renal sympathetic nerves in mediating the renal functional responses to intrarenal nNOS inhibition. Thus, we also evaluated the effects of intrarenal L-SMTC administration in acutely denervated TGR and HanSD. Expression of nNOS mRNA in the renal cortex was significantly increased in TGR compared with HanSD. Intrarenal administration of L-SMTC decreased the glomerular filtration rate (GFR), renal plasma flow (RPF) and sodium excretion and increased renal vascular resistance (RVR) in HanSD. In contrast, intrarenal inhibition of nNOS by L-SMTC did not alter GFR, RPF or RVR and elicited a marked increase in sodium excretion in TGR. This effect of intrarenal L-SMTC was not observed in acutely denervated TGR. These results suggest that during the developmental phase of hypertension TGR exhibit an impaired renal vascular responsiveness to nNOS derived NO or an impaired ability to release NO by nNOS despite enhanced expression of nNOS mRNA in the renal cortex. In addition, the data indicate that nNOS-derived NO increases tubular sodium reabsorption in TGR and that the renal nerves play an important modulatory role in this process., L. Červenka, H. J. Kramer, J. Malý, I. Vaněčková, A. Bäcker, D. Bokemeyer, M. Bader, D. Ganten, K. D. Mitchell., and Obsahuje bibliografii