Inactivation of Estrogenic Hormone of the Ovary by the Liver

Abstract

Very small proportions of estrogens are recovered in the excreions from animals to which they have been administered. Evidence n support of the theory that the liver is responsible for the inactivation has been obtained by Zondek 1 and many others. 2 3 Recently, Israel, Meranze, and Johnston 4 found that alphaketohydroxy estrin was rapidly inactivated when added to the perfusate of a heart-lung-iver perfusion system, while no inactivation occurred in perfusion systems consisting of heart and lung, without the liver. These findings suggest that estrin, in the quantity liberated into the blood stream by the ovaries, is inactivated when it reaches the liver.

In order to test this theory, homotransplants of ovaries were made to the mesenteries of a group of rats. The venous drainage was such that any secretion produced by the transplants must pass through the liver before reaching the organs (uterus, vagina, pituitary) upon which the effect of the hormone could be determined. Homotransplants of the ovaries to the axillary region in another group of rats served as controls.

Microscopic sections revealed that the transplants grew well at both sites. Those rats whose ovaries had been transplanted to the axilla resumed their cycles in from 8 to 20 days after the operation. On the other hand, animals whose ovaries had been transplanted to the mesentery showed no evidence in the vaginal smear of coming into heat after 40 days. The pituitaries of 4 of the latter group of animals, assayed by the Lauson, Heller, Sevringhaus technic, 5 were of the potency order of the pituitaries of castrates, in spite of the fact that microscopic sections of the transplants revealed functional ovarian tissue with large follicles and corpora lutea. In 12 of the animals mesenteric transplants of the ovaries were retransplanted to the axillary region. Ten of these animals survived the operation, and in all but one estrus reappeared in from 8 to 20 days after retransplantation.