Non uniform effect of estradiol on the rat skeleton.

Pharmacological doses of estradiol administered to rats increased the Ca mass of their femurs through a significant reduction in the rate of Ca resorption. On a body basis, the same animals showed increased rates of skeletal Ca deposition and resorption and no effect on the skeletal mass. The non uniform effect of estradiol on the skeleton, if confirmed in the human being, may limit the applicability of estrogenic treatment.