تغييرات حساسيت به انسولين در پي گنادكتومي يك طرفه و دوطرفه ، تجويز استراديول

Effects of uni- and bilateral gonadectomy and administration of estradiol, progesterone and testosterone with pancreatic B-cell KATP channels Mocker or opener on insulin sensitivity in rats

Introduction: From clinical point of view, study on the effects of sex steroid hormones on insulin secretion and sensitivity is important in related disorders treatment. Therefore, the main purpose of the present study was to clarify the effects of sex steroid hormones on insulin sensitivity in rats. According the roles of pancreatic B-cells ATP-sensitive K+ (K471) channels in insulin secretion, the effects of the hormones on pancreatic KATP channels were also studied. Methods: Diazoxide (30mg/kg/dory) or verapamil (100mg/kg/day) was used as pancreatic B-cell opener or blocker, respectively. Testosterone (50mg/kg/day as replacement dose in hi-orchideclomized rats and 10 mg/kg/day in intact male animals) and progesterone (20 mg/kg/day) and estradiol (200,ug/kg/day) in, female ruts, were also used. Mule rats were divided into control, uni- and hi--orchideclomized, testosterone receiving bi-orchidectornized, diazoxide or verapamil and also "testosterone+diazoxide or verapamil" receiving animals. Female rats were divided into control, uni- and bi-ovariectomized, progesterone or estradiol receiving bi-ovariectomizedd, and progesterone, estradiol, diazoxide or verapamil receiving and also "Progesterone + diazoxide or verapamil" receiving animals. The period of 4 weeks was considered for each experiment. After weeks, serum glucose and insulin were measured and insulin sensitivity (glucose/insulin ratio) was compared statistically between the groups. Results: In male rats, hi-orchidectomy, and diazoxide or "diazoxide + testosterone" treatment caused an increase but uni-orchidectomy, and testosterone, verapamil or "verapamil + testosterone" treatment resulted in decreasing of insulin sensitivity. In female rats, uni- and bi-orchidectomy, and progesterone, diazoxide or "progesterone diazoxide or verapwnil" treatment lead to an increase but estradiol or verapwnil treatment resulted in decreasing of insulin sensitivity. Conclusion: Testosterone and estradiol were insulin sensitivity reducer but ovariectomy, bi-orchidectomy and progesterone were insulin sensitivity enhancer in rats. The results indicated that presumably testosterone was not contributed in closing or opening of pancreatic B-cells KATP channels but progesterone influenced insulin sensitivity by its inhibitory acting on pancreatic KATP channels.