Diabetes mellitus induces vaginal tissue fibrosis by TGF-beta(1) expression in the rat model

The commonly reported sexual problem in women with diabetes mellitus is lac k of vaginal lubrication. It is our hypothesis that reduced vaginal lubrica tion in diabetic women may result from the structural changes of the vagina . The aim of this study was to investigate in the diabetic rat model the va ginal structures using histochemistry, and the expression of TGF-beta (1) u sing immunohistochemistry, Twenty female Sprague-Dawley rats (200-210 g) we re divided into two groups: control and experimental. ne experimental group (n = 10) received intravenous injection of streptozotocin (50 mg/kg), Afte r 4 weeks, blood glucose levels were measured, and the vagina of the rat wa s excised. Serial sections of the vagina were used to perform hematoxylin a nd eosin (H & E) and Masson's trichrome stains, and for immunohistochemistr y to identify TGF-beta (1) expression. The mean blood glucose concentration s were 67 +/- 11 mg/dL (range; 50-85) in the control group and 522 +/- 61 m g/dl (range; 429-590) in the experimental group. In the diabetic animals, v aginal tissue revealed reduced epithelial layers and decreased vaginal subm ucosal vasculatures compared to the control animals. The collagen connectiv e tissue in the submucosal area of The diabetic animal tissue showed a dens e and irregular, distorted arrangement. The immunoreactivity of TGF-beta (1 ) in the diabetic animals was Prominent in the collagen connective tissue, fibroblasts, and smooth muscle fibers, whereas no immunoactivity was detect ed in the vaginal structures of the control animals. Diabetes mellilus may induce vaginal tissue fibrosis bi, TGF-beta (1) expression in the rat model . This implies that reduced vaginal lubrication in the diabetic women mali, result from the structural changes of the vagina.