Investigation of the effects of insulin on the ovarian follicles in rats with diabetes at electron and light microscopic level

Diabetes is a metabolic disorder characterized by chronic hyperglycemia and derived from the defects in secretion or effect mechanisms of insulin and associated with failure in fat, protein and carbohydrate metabolism1. In treatment of diabetes, multiple daily insulin applications are used in order to control the metabolism. The reproductive problems in patients with diabetes acquire different dimention when patients received insulin treatment. In addition to menstruel irregularity, hypogonadism and findings of early menopause have been reported in patients with diabetes. On the other hand it has been reported in clinical investigations that, as a result of ovarian derived hyperandrogenism, polycystic ovaries can be seen in patients received insulin treatment2,3,5. However there are not enough researches that include structural changes occur in the ovaries in patients with diabetes and in patients received insulin for regulation of metabolism. The aim of present study is to investigate structural changes observed in the ovaries of the rats that experimentally induced with diabetes and received insulin therapy, by light and electron microscopic analysis. For this reason, 30 adolescent (50 days old) female rats will be divided into three groups. Rats in the first group (n=10) will be injected only 0.1 M citrate buffer and considered as control group. The second group (diabetes group, n=10) will be injected a single dose of 60 mg / kg i.p. streptozotocin8 and the third group (diabetes+insülin group, n=10) will be injected a single dose of 60 mg / kg i.p. streptozotocin and after that 2 IU insülin9 will be injected subcutanously daily twice in the mornings and evenings for 4 weeks. After 72 hours from streptozotocin injection, blood samples will be obtained from the tail vein of streptozotocin-injected rats and fasting blood glucose levels will be measured by glucometer. The rats which have ≥250 mg / dl blood glucose level will be included in the study. Blood glucose levels of the rats of the third group will be measured daily and 2IU doses of insulin will be injected subcutanously in mornings and evenings during four weeks. At the end of four weeks, the blood and ovarian tissues will be taken from all animals under anesthesia. FSH, LH, estrogen, progesterone, androstenedione, and testosterone levels will be measured in blood serum, and ovarian tissues will be processed for light and electron microscopic evaluations. These microscopic evaluations will make a contribution to understanding the effects of diabetes and insulin which is used for regulation of metabolism in diabetic patients on follicule development in ovaries. Key words: Diabetes, follicle development, insulin, ovary