OBJECTIVETo establish a blood glucose fluctuation model in diabetic rats.

METHODSMale SD rats were randomly divided into 2 groups, namely normal group and diabetes group. Rat model of diabetes was established by single intraperitoneal injection of streptozotocin (STZ) and then divided into sustained high blood glucose group and blood glucose fluctuation group. Rat model of blood glucose fluctuation was established by subcutaneous injection with regular insulin or gavaging of glucose twice daily in diabetic rats. The general condition, body weight, daily blood glucose levels of 5 different times, daily average blood glucose (MBG), standard deviation of daily average blood glucose (SDBG), the maximum amplitude of glycemic excursions (LAGE), fasting serum insulin (FINS) and pancreatic tissue pathology were observed.

RESULTSRats in blood glucose fluctuation group and sustained high blood glucose group developed symptoms of polyphagia, polyuria and polydipsia. Though significant differences in body weight were observed at different time (P<0.01), no significant differences were found among the three groups (P>0.05). After 6 weeks of blood glucose fluctuation, MBG, SDBG and LAGE in blood glucose fluctuation group and sustained high blood glucose group were increased significantly than those in normal group (P<0.01), the level of FINS decreased markedly (P<0.05). SDBG and LAGE in blood glucose fluctuation group were higher than those in sustained high blood glucose group (P<0.01). Islet of diabetic rat became atrophy, irregular shape, sparse distribution, and decreased in number, and the changes were more obvious in blood glucose fluctuation group.

CONCLUSIONRat model of blood glucose fluctuation can be successfully established by subcutaneous injection of regular insulin of gavage of glucose twice daily in diabetic rats.