Investigation On The Relationship Between Gastric Emptying And Level Of Plasma Ghrelin And Obestatin In Diabetic Rats

Objective To investigate the effects of plasma ghrelin, obestatin and ghrelin/obestatin (G/O) on the gastric emptying in early stage of diabetes mellitus.Methods Sixty male Wistar rats were randomly divided into normal control group(NC group), diabetes mellitus group(DM group), insulin-treated group(INS group) with 20 in each. The intraperitoneal injection of streptozotocin was used to induce type 1 diabetic models in the later two groups. From the fourth day after the injection, INS group was given intermediate-acting insulin four International Units by hypodermic injection every day, and the other two groups were given equal volume normal saline every day. After two and six weeks, half of each group was taken out for the experimentation. The gastric emptying of rats was measured by intragastric administration of phenol red, and the level of plasma ghrelin and obestatin were detected by the Enzyme-Linked Immunosorbent Assay (ELISA).Results Two weeks and six weeks later, the body weight in DM group decreased and its blood glucose level increased compared with those in NC group (P<0.001,0.001). The gastric emptying, the level of plasma ghrelin and obestatin and G/O in DM group increased compared with those in NC group(P<0.001,0.001,0.01,0.05). Two weeks and six weeks later, the body weight in INS group increased and its blood glucose level decreased compared with those in DM group (P<0.001,0.001). The gastric emptying in INS group decreased compared with those in DM group(P<0.01), and the level of plasma obestatin in INS group increased compared with the other two groups(P<0.001, 0.05).Conclusions The method of hige-dose streptozotocin intraperitoneal injection to induce type 1 diabetic models is one of the perfect ways to form animal models, because it is simple and convenient, and it has a high achievement ratio. In early stage of diabetes mellitus, the gastric emptying, the level of plasma ghrelin and obestatin all increased significantly, and accompany with the level of G/O. The increase of plasma G/O may be one of the important factors for the promotion of gastric emptying. The effect of extrinsic insulin on plasma obestatin may be related to the regulation of gastric emptying in early stage of diabetes mellitus.