Abstract: The purpose of this study was to observe the changes of gastric motility, gastric myoelectric activity in DGP and nitric oxide synthase(NOS)in experimental diabetic rats. Thirty male Wistar rats were divided into 2 groups. Diabetes mellitus was induced in these rats by streptozotocin administration in one group. The other group was the control group. Gastric motility and myoelectrical activity were recorded in both groups. Changes in NO synthase activity and expression were determined by using NADPH diaphorase histochemical staining and nNOS immunohitochemical technique in these groups. Gastric motility measurement showed that the frequency of gastric contraction and the average contractile amplitude in diabetic rats were reduced significantly. Gastric myoelectrical measurement showed that the frequency and amplitude of slow wave were also reduced. NO synthase activities in intermusclar plexuses, circular and longitudinal smooth muscles and vascular endothelium were increased in diabetic rats. Gastric motility and myoelectrical activity were depressed in diabetes mellitus. Increase in NO synthase activity might be related to the depression of gastric motility in diabetes mellitus.

Key words: diabetic rat, migrating motor complex, eletrogastrogram, nitric oxide synthase