evaluation of renal glomeruli number changes in male diabetic rats by using stereological methods

introduction: due to the relation between structure and function of renal glomeruli, the study of glomeruli is very important to the understanding of initiation and progression of diabetic glomerulopathy. it seems that glomeruli disappear during the course of diabetic nephropathy without leaving recognizable corpuscles. this study was aimed to show diabetes mellitus effects on changes in renal glomeruli number in male diabetic rats. material and methods: forty-eight male wistar rats were randomly divided into eight groups. diabetes was induced by an intravenous injection of streptozotocin 90 mg/kg in 1.0 ml of acetate buffer in four groups and the other four groups were taken as control. the animals were anesthetized and dissected three months, six months, nine months and twelve months after administration of streptozotocin respectively. then fixation, sampling, processing, embedding in paraplast, sectioning and staining were performed followed by stereological glomerular counting by means of an unbiased new method of stereology, physical disector/fractionator. data were analysed by mann-whitney u test. results: the counting of glomeruli in the group of cases in comparison with their controls showed that three, six and nine months streptozotocin induced diabetes had no statistically significant effect on glomerular number (p> 0.05) while in long terms, twelve-months, reduction of glomeruli was significant (p= 0.030). conclusion: induction of diabetes mellitus by streptozotocin in a period less than 9 months has no effect on renal glomeruli number, whilst during 12 months diabetes mellitus may cause a significant reduction in glomerular number.