Histologic study of the early events in oxalate induced intranephronic calculosis.

The early phases of calcium oxalate crystal formation in rat kidneys after intraperitoneal challenge with sodium oxalate were examined. From the results we conclude that the crystals are formed intraluminally in the proximal tubules of the renal cortex. The size, number, and distribution of calcium oxalate particles depend on the amount of sodium oxalate injected and the time interval after its injection. Tubular necrosis and dilation were evident after administration of higher doses of sodium oxalate. The papillary tip and corticomedullary junction were the preferential sites for crystal localization after longer periods of injections of higher doses of sodium oxalate.