An oestrogen-linked nephrocalcinosis in rats.

A non-familial nephrocalcinosis, unrelated to hypercalcaemia, and occurring in female rats only, is described. Oestrogens were found to be essential since ovariectomised rats did not develop the condition. Replacement therapy with oestrogens following gonadectomy in animals of either sex resulted in kidney calcification. There is also evidence that an unidentified dietary factor is concerned in the initiation of the nephrocalcinosis. Histological appearance of mineral deposits coincided with increments in renal calcium and phosphorus. Grossly, calcification commenced at the cortico-medullary junction, spreading to involve the medulla. Electron microscopy revealed the presence of both intratubular and intracellular lamellated deposits in the nephron. These deposits were isolated by density centrifugation and chemically characterised.