Histology of the Ovary of Hypophysectomized Rats Treated with Urinary Hebin

Abstract

The treatment of hypophysectomized rats with hebin, the gonad stimulating substance from human pregnancy urine, indicates that the response is conditioned by the time intervening between hypo-physectomy and the beginning of hebin administration and by the influence of hebin administration, immediately after hypophysectomy, upon a later treatment with hebin, after an intervening period of rest.

Female albino rats, weighing about 120 gm. when completely hypophysectomized by Dr. Smith's method,∗ showed the usual ovarian changes with atresia of follicles, almost complete absence of follicular development, granulosa atrophy, interstitial tissue hyperplasia and production of wheel cells described by Selye et al. 1

In all cases one ovary, removed at some crucial period in the experiment, was compared histologically with the second ovary, removed at the end of the experiment.

Urinary hebin† failed to inhibit ovarian degeneration or cause repair in 16 animals treated shortly after hypophysectomy. Serial sections from 5 of the animals showed that the ovary was converted into a lutein-like mass in which it was difficult to distinguish the individual component parts. Occasional small and medium sized follicles were found. The origin of the lutein is apparently from diverse kinds of cells but primarily from theca. The production of new corpora lutea reported by Leonard and Smith 3 is somewhat uncertain in our animals.

Other animals similarly treated and then allowed to rest for 12 to 20 days showed a return to the involuntary state as if no hebin had been administered. The previously luteinized theca changed over to the wheel cell type. A few luteinized follicles persisted but did not exceed in number those found in the ovaries of untreated hypophysectomized rats of comparable periods after hypophysectomy.

In 5 animals the terminal response to the injection of hebin after a 6 to 10 weeks interval after hypophysectomy was quite similar to the response to hebin administration immediately after hypophysectomy. The difference was that theca luteinization in delayed hebin administration occurred as a transformation of previously formed wheel cells into lutein cells while no such intermediate wheel cell formation occurred when hebin was injected immediately after hypophysectomy.