Abstract:

Objective   To investigate gastric emptying and plasma ghrelin and obestatin levels in the early stages of streptozotocin-induced diabetic rats, and to explore the relationship between them.  MethodsForty Wistar rats were randomly divided into four groups: the normal control group(NC group), the diabetes mellitus group(DM group), the low-dose insulin-treated group(LD group) and the high-dose insulin-treated group(HD group).  Rats were made diabetic by intraperitoneal injection of streptozotocin (STZ). Each rat in the LD group and HD group received 4U and 8U Humulin NPH by subcutaneous injection every day respectively. Two weeks after the STZ injection, gastric emptying,  plasma ghrelin levels and obestatin levels were determined. ResultsTwo weeks after the STZ injection, blood glucose levels and plasma ghrelin levels increased significantly in the DM group compared with those in the other three groups(P＜0.01). Although the blood glucose levels still increased significantly in the HD group compared with those in the NC group(P＜0.01), the plasma ghrelin levels had no statistical difference between the two groups（P＞0.05）. The plasma obestatin levels increased significantly in the DM, LD and HD groups compared with those in the NC group(P＜0.01), but those in the other three groups had no statistical differences (P＞0.05). Gastric emptying accelerated significantly in the DM group compared with those in the other three groups(P＜0.01). Although gastric emptying slowed significantly in the HD group compared with those in the DM and LD groups(P＜0.01), it accelerated significantly compared with that in the NC group(P＜0.01). ConclusionThis study suggests that gastric emptying significantly accelerated during the early stages of streptozotocin-induced diabetic rats. Elevated endogenous ghrelin may play  an important role in it and the role of endogenous obestatin needs further study.

Key words: Diabetic mellitus; Gastric emptying; Ghrelin; Obestatin; Rats, Wistar