Renal tissue of six diabetics having proliferative retinopathy was obtained before and one to two years after pituitary surgery and examined by light and electron microscopy. Successful pituitary ablation was followed by significant reduction in the thickness of the glomerular capillary basement membrane, restoration of the atrophic endothelial and mesangial cells to their normal appearance, persistence of the morphological features suggesting overactivity of the epithelial cells and no improvement in the arteriolar lesion.
These observations and changes suggest that diabetic nephropathy results from the development of several separate though inter-related lesions each of which may be variously influenced by the metabolic disturbance, the inherited diabetic diathesis or pituitary activity. Hypophysectomy will not alter the progressive clinical course of diabetic kidney disease if significant renal arteriosclerosis is present.