Polyvinyl Alcohol Nephrosis: Relationship of Degree of Polymerization to Pathophysiologic Effects.

Abstract

Polyvinyl alcohol of 3 different molecular weights, 37,000, 133,000 and 185,-000, was injected daily and subcutaneously into rats on a high NaCl intake. The lowest molecular weight material was not demonstrated in any of the tissues examined and, over the period studied, produced only mild elevation of blood pressure in a third of the animals which received it. High molecular weight PVA infiltrated a number of organs and tissues. Most prominently it affected renal glomeruli causing swelling and multiplication of endothelial and epithelial cells and often crescent formation. Mild hypertension affected half of the animals and heart, kidneys, liver and spleen were enlarged. Neither polymer caused polydipsia. The intermediate polymer produced severe polydipsia, a nephrotic syndrome associated with ascites and edema, severe hypertension, marked renal damage with severe glomerulonephritis, often hemorrhagic, and widespread cardiovascular lesions. The pathologic effects depend more upon the molecular size than upon chemical structure.