ABSTRACT
Diabetes mellitus [DM] is a chronic metabolic disorder brings great danger to human health. Low-dose-rate radiation modulates various biological responses including carcinogenesis, immunological responses and diabetes. This study examined the effect of low doses of irradiation on the pathological and ultrastructural progression of type I diabetes in rats inducted by Streptozotocin. The present study was done on 80 healthy adult albino male rats 9 weeks age, in the weight range from [150-200 gm]. Rats were grouped to 4 groups they were cared according to the Guiding Principle in the Care and Use of Animals. Diabetes was induced by a single intraperitoneal injection of freshly prepared Streptozotocin [STZ- 45 mg/kg b.w.]. Whole body gamma irradiation was performed using Caesium -137. Animals were exposed to fractionated dose levels of 0.5 Gy/week of gamma-radiation for 3 and 6 weeks. The body weight, blood glucose and insulin levels were measured after 3 and 6 weeks. Small blocks of pancreatic tissues of different groups were removed and prepared for pathological and ultrastructure examination. An elevated level of glucose and decreased level of insulin in blood were first detected at 3 and 6 weeks of age in the STZ treated rats. There was significant and remarkable tendency of gaining normal levels of both blood glucose and blood insulin by irradiation exposure especially after 6 weeks of irradiation. Both suppression of cell death and cellular injury induced by STZ were also observed by EM examination in 3 week and 6 weeks. The present results indicated that treatment with 0.5 Gy gamma rays suppresses progression of type I diabetes in STZ rats