Study Of Relationship Between Selenoproteins And Pubertal Type 2 Diabetes Mellitus

Part 1: Characteristics of Pubertal Rat Models with Insulin Resistance and Type 2 Diabetes MellitusThe models of pubertal rats (7 weeks of age) and adult rats (11 weeks of age) with insulin resistance were established by high-fat feeding. Rat model of type 2 diabetes mellitus was established by high-fat feeding plus low-dose streptozotocin (STZ) injection (30mg/kg). Euglycemic-hyperinsulinemic clamp technique was performed in two models of pubertal rats, and differences among the three rat models of blood pressure, plasma lipids, fasting glucose, fasting insulin concentration and insulin sensitivity were compared. The data showed that average glucose infusion rates (GIRso-i2o) were lower in puberty male and female rats with high-fat diet than those in rats with regular chow, and the change was more significant in female rats than that in male rats. The plasma testosterone level decreased in male rats but increased in female rats. Correlation analysis showed that the plasma testosterone concentration was positively correlated with GIReo-no in male rats, and negatively correlated with GIReo-iao in female rats. Blood pressure was higher in male rats than that in female rats. After 6 weeks high-fat diet was fed and treatment with STZ, both fasting blood glucose and postprandial blood glucose increased while GIReo-no declined in puberty male rats. Both plasma triglycerides (TG) and plasma lower-density lipoprotein (LDL-c) were increased in pubertal male rats with insulin resistance, and dyslipidemia was aggravated in adult rats with insulin resistance. These results show that puberty rats with insulin resistance or type 2 diabetes were successfully established in pubertal Wistar rats by high-fat diet and high-fat feeding plus STZ injection, respectively. The reduction of insulin sensitivity is related to abnormality of testostrone level. Meanwhile, blood pressure increased and plasma lipids were abnormal. In adult rats with high-fat diet insulin sensitivity was5comparable to that in puberty rats with insulin resistance, but dyslipidemia was aggravated.