Experimental calcium oxalate nephrolithiasis in the rat. Role of the renal papilla.

Abstract

Calcium oxalate nephrolithiasis in rats, induced by single intraperitoneal injection of sodium oxalate, is associated with pathologic changes in the renal papillary tip. Calcium oxalate crystals appear in the tubular lumens, in the intercellular spaces between epithelial cells, and attached to the tubular epithelial basal lamina. Unusual paracrystalline structures also develop in the distal tubule associated with the basal lamina. Speculations are made about the role of these structures. The epithelial changes are primarily necrotic and are similar to those described in experimental papillary necrosis. Complete morphologic recovery occurs in 1-2 weeks.