[Establishment of rat model of type 2 diabetes complicated with hypertension]

To establish type 2 diabetic model in rats complicated with hypertension.

Sixty five SD male rats were divided into normal control group, 1%NaCl water-treated group, 20 mg/kg STZ-1% NaCl-treated group, 30 mg/kg STZ-1%NaCl-treated group and 40 mg/kg STZ-1% NaCl-treated group according to random digit table(n=13).Except that rats in the normal control group were fed with ordinary diet, rats in the other groups were fed with high-fat diet for 4 weeks, then maintained with free access to rat chow and 1% NaCl drinking water for 9 weeks. In addition, rats in streptozotocin(STZ) groups were received STZ at a different dose(20 mg/kg, 30 mg/kg, 40 mg/kg)respectively by intraperitoneal injection at the end of the fourth week. The experimental period lasted 13 weeks. During the study, the general condition, body weight, average food intake, blood glucose, blood pressure, blood lipids and plasma insulin levels of each rat were tested.

After STZ injection, tests showed body weight was significantly reduced (P<0.05), average food intake and fasting/random blood glucose level were increased significantly (P<0.05); blood pressure was obviously risen (P<0.05)and the average value of systolic blood pressure was reached 150 mmHg into hypertensive stage at the 4^th week and stable at 150~170 mmHg for five weeks(before the end of experiment); the level of plasma insulin was higher significantly (P<0.05), the level of plasma triglyceride(TG)was descended significantly (P<0.05)at the 13^th week of the experimental period, each of which was only in 30 mg/kg STZ-1% NaCl-treated rats and 40 mg/kg STZ-1% NaCl-treated rats as compared with non-treated rats or 1% NaCl water-treated rats.

The method that the rat was fed with high-fat diet for 4 weeks, then, received intraperitoneal injection of 30~40 mg/kg STZ combined with feeding 1% NaCl drinking water, which can induce insulin resistance in rats with type 2 diabetes mellitus and hypertension.