Effects of diabetes and elevated glucose on nitrergic relaxations in the isolated duodenum of the rat

Abstract

Nitrergic relaxations of the isolated duodenum, induced by streptozotocin, were investigated in the experimental 8-week diabetes rat model. The effects of elevated glucose were also examined in the incubated duodenal muscles (in Krebs-Henseleit solution containing 44 mM glucose for 6 h) taken from nondiabetic rats. The relaxations induced by electrical field stimulation (EFS) and nicotine were significantly reduced in diabetic rats compared with control rats. Incubating of duodenal tissues in medium containing elevated glucose revealed significantly impaired relaxations to EFS and nicotine compared to responses obtained after normal glucose incubation. However, the relaxant responses to sodium nitroprusside and papaverine were similar in all groups. Incubating in hyperosmolar solutions containing sucrose, the relaxant responses were not affected. In conclusion, impairment of NO-mediated relaxations in diabetes may be related to hyperglycemia. The alterations caused by elevated glucose are not due to a hyperosmotic effect because the same concentration of sucrose had no effect on the relaxations.

Etanercept Improves Cognitive Performance and Increases eNOS and BDNF Expression During Experimental Vascular Dementia in Streptozotocin- induced Diabetes

“…DM was induced in rats by using our previously reported method with a minor modification [26]. In brief, STZ was dissolved in 0.1 M sodium citrate buffer (pH 4.4) and administered at 50 mg/kg via the intraperitoneal route.…”

Choline treatment affects the liver reticuloendothelial system and plasma fatty acid composition in diabetic rats

“…In each radiotracer study, rats were divided into four groups: control (C group), diabetic group (D group), choline-treated diabetic group (Ch/D group) and choline-administered group (Ch group). Diabetes mellitus was induced in the rats of D and Ch/D groups, by an intraperitoneal (ip) injection of 55 mg kg À1 streptozotocin (STZ) (freshly dissolved in 5 mM citrate buffer, pH 4Á5) (Akbarzadeh et al, 2007;Utkan et al, 2009). Blood glucose was tested before induction of diabetes, and on the second day, in the first week and in the second week after induction of diabetes, for all groups, using FreeStyle Freedom â Lite Blood Glucose Monitoring System.…”

Myosin Va but Not nNOSα is Significantly Reduced in Jejunal Musculomotor Nerve Terminals in Diabetes Mellitus

“…Mechanical studies have confirmed diminution of EFS-mediated nitrergic relaxations in diabetic enteric tissues like ileum and mid-colon ( 3 – 7 ). Some of these studies have also demonstrated restoration of nitrergic mediated responses in diabetic tissues with externally added NO donor to the organ bath ( 4 – 6 ), indicating that the diminution of nitrergic function in diabetic gut tissues resulted primarily from reduction or inhibition of NO synthesis within the pre-junctional nerve terminals.…”