Pathological changes in streptozotocin induced diabetes mellitus in the rat.

The structural changes in kidneys of diabetic rats induced by streptozotocin were compared with those of age-matched control animals. Degenerative changes were found in the distal tubules of diabetic rats as early as 2 weeks following the onset of diabetes and by one month the entire distal tubule was severely affected. Fibrinoid lesions were also found in diabetic rats after 4 weeks of the disease and became more frequent subsequently. IgG, albumin but not C3 were also found in the glomerular basement membrane of diabetic rats. Diabetic glomerulosclerosis was present only after several weeks, affected glomeruli showed diffuse mesangial sclerosis and only occasionally nodular sclerosis. Diabetic animals developed renal cortical adenomas and mesenchymal tumours after several months.