Received: 15 July, 2012 Accepted: 2 Sep, 2012

  Abstract

  Background & Aim: Diabetes is a metabolic disorder which affects whole systems in body including female reproductive system. Moreover, diabetes is an effective cause to infertility. Metformin is of the most common drugs using to control of hyperglycemia in patients. The aim of this study was surveillance of ultrastructural changes of ovarian follicles in diabetic rats and evaluation of Metformin efficiency.

  Materials & Methods : Thirty-six adult Sprague-Dawley female rats (170-210g) were studied in 3 groups (Control, diabetic and diabetic treated by metformin). In second and third groups, rats were induced diabetes by streptozotocin and the third group were treated by metformin monohydrochloride. At the end of experience period, rats were euthanized and their right ovary -after preparation- were observed by Transmission Electron Microscope (TEM) to survey objective factors.

  Results : In comparison with control group, shape shrinking and size decreasing in granulosa cells, nucleus disorder and shrinking, decline in nucleus activity (increasing of dark chromatin), reduction in number of cytoplasmic organelles and their unnatural appearance, accumulation of lipid droplets in cytoplasm, gaps among corona radiata cells and their spacing from zona plucida were observed in diabetic group. Mitochondrial homogenization and decreasing in number, ballooning in cristae in some mitochondria, swelling of rough and smooth endoplasmic reticulum are of the most obvious organellar changes in diabetic group.

  Conclusion : Diabetes causes ultrastructural changes of apoptosis to granulosa cells and leads to atresia in growing follicles. Treatment with metformin can cause better conditions to mentioned cases in diabetic patients.