Effects of methyltestosterone and oophorectomy in acute experimental mediocalcinosis in the rat.

Virgin female rats treated with vitamin D (VD) overdoses developed acute aortic mediocalcinosis. Methyltestosterone (MT) treatment inhibited calcinosis and/or accelerated the resorption of aortic calcium deposits. Oophorectomy performed four weeks after the beginning of VD treatment had no effect on mediocalcinosis. Furthermore, the rats that had been spayed seven months before VD were not protected by MT treatment as those that had been spayed four weeks after VD. Cartilaginous metaplasia, in a more or less advanced stage, was a frequent histological finding in the aorta.