Pancreatic islet allograft prevents basement membrane thickening in the diabetic rat retina.

Progressive basement membrane thickening is a characteristic structural abnormality in diabetic tissues including the retina. We examined the effect of pancreatic islet allotransplantation on basement membrane thickening and irregularities in retinal capillaries of the streptozotocin-diabetic rat. Diabetic animals received intraportal or intracerebral pancreatic islet allografts. Animals with functioning allografts demonstrated euglycaemia and a normal body weight gain during the 400-day post-transplantation period. The characteristic thickening of capillary basement membranes was completely prevented in animals with successful transplantation. The present findings suggest that islet allotransplantation may be a rational therapeutic approach in the treatment of diabetes mellitus and the prevention of ensuing secondary complications.