The Potential Antidiabetic Activity of some Alpha-2 Adrenoceptor Antagonists

This thesis is concerned with the evaluation of the potential antidiabetic activity of some alpha-2 adrenoceptor antagonists. In addition, an attempt is undertaken to elucidate the possible mechanism (s) of this activity.The effect of alpha-2 adrenoceptor antagonists (i.e. yohimbine and efaroxan) on plasma glucose and insulin levels was studied in three categories of rats: non-diabetic control, type-I and type-II diabetic rats.Type-1 diabetes (Insulin-dependent diabetes mellitus, 100M) was induced tJy an intraperitoneal injection of 65 mg/kg streptozotocin in 9-week-old male wistar rats. Type-2 diabetes (Non-insulin dependent diabetes mellitus, NIOOM) was induced in one-day-old male wistar rats by treating them with a single intraperitoneal injection of 95 mg/kg streptozotocin.A glucose tolerance test was performed in this study to check whether type-lor type-II diabetic rats were intolerant to oral glucose. Our results show that the oral administration of 2 g/kg D-glucose to non-diabetic control rats produced a rapid increase in the plasma glucose and insulin levels, followed by a progressive decline until they nearly reached control values. In type-I diabetic -rats, there was a marked intolerance to oral glucose associated with a concomitant failure in induction of insulin secretion. In type-II diabetic rats, there