GLOMERULAR BASEMENT-MEMBRANE THICKNESS FOLLOWING ISLET TRANSPLANTATION IN THE DIABETIC RAT

Abstract

Glomerular basement membrane (GBM) thickness was measured in diabetic rats prior to and following islet transplantation. Over the course of the experiment (from 7-13 mo. of diabetes) GBM thickness in diabetic animals exceeded that of littermate controls. After 7 mo. of diabetes, a group of animals received successful intraportal transplants of neonatal pancreatic tissue. GBM thickness at 2 and 6 mo. following islet transplantation matched the thickness in nontransplanted diabetic rats and exceeded that in control animals. Failure to reverse GBM thickening in diabetic rats following islet transplantation may be due to very slow rates of GBM turnover in the rat. Previous work demonstrated normalization of urinary albumin excretion after islet transplantation, suggesting that GBM thickening, per se, is not a significant factor causing albuminuria in rats with longstanding diabetes.