The electronmicrsoscopic and immunohistochemical evaluation of glomerular changes in an experimentally induced hypertensive and diabetic rat model

The concurrence of Diabetes Mellitus and hypertension has a progressive effect on renal damage. In this study experimental diyabetes and nephrectomy have been applied together and separately to evaluate their effects on kidneys both ultrastructurally and immunohistochemically and to investigate lipoic acid, an antioxidant as a possible therapeutic agent.Wistar rats were divided into 8 groups (n=7). Group I; Control, group II; DM, group III; 5/6 Nx, group IV; LA, group V; 5/6 Nx+DM, group VI; DM+LAT, group VII; 5/6 Nx+LAT and group VIII; 5/6Nx+DM+LAT. Diyabetes was formed by 45mg/kg STZ injection and for hypertension nephrectomy 5/6 model was applied. dl-?-Lipoic acid 30mg/kg/day was fed by oral gavage for 8 weeks. Kidney tissue was stained by HE, Masson Trikrom and PAS. AT1, VEGF, ET-1 and Caspase-3 antibodies were labelled immunohistochemically. GBM and bowman outer shell thickness were measured ultrastructurally. Creatinine and BUN levels were measured in blood biochemically.In groups where diyabetes and nephrectomy were applied separately and together, glomerulosclerosis, mononuclear cell infiltration, interstitial fibrosis, vascular and tubular dilatation and hyalin deposition and degeneration of tubular structures were seen in glomerules. When renal damage was evaluated histomorphometrically, bowman capsul thickness, glomerule diameter, glomerule/nucleus ratio, renal scar area and glomerulosclerosis values, and ultrastructural GBM and BCT were increased in diyabetes and nephrectomy groups. Tubulointerstitial and glomerular AT1 was decreased but VEGF, ET-1 and Caspase-3 were increased. Creatinine and BUN values were increased in the same groups. Groups which were given LA had values similar to the control group.In the light of these results we have come to the conclusion that diyabetes and hypertension together increases the rate of renal injury and lipoic acid has a protective/therapeutic effect on kidneys.