A COMPARISON OF RENAL CALCIFICATION PRODUCED BY PARATHYROID EXTRACT OR CALCIUM GLUCONATE

Abstract

Renal calcification was produced in mice by the administration of parathyroid extract or 10% calcium gluconate. The pattern of renal calcification produced by parathyroid extract differed from that produced by calcium gluconate in four respects: (1) Calcified and (2) necrotic renal tubular epi-thelial cells formed the background for most of the calcification. This was seen especially at the corticomedullary junction. In addition, there was (3) depletion of alkaline phosphatase activity and (4) thickening of the renal tubular basement membranes in the affected areas. The last two alterations are considered to be nonspecific and secondary to the necrosis of renal tubular epithelial cells. It is suggested that parathyroid extract has a direct effect on renal tubular epithelium and that the calcification is not related either to the hypercalcemia produced by parathyroid extract or the action of parathyroid extract on renal tubular basement membrane. In addition, we found no evidence to support the hypothesis that polysaccharide delivered to the kidney as the result of the action of the parathyroid extract elsewhere in the body, was altered so that it becomes calcifiable.