Effect of Pregnancy on the Rat Ovary Transplanted to the Spleen. ∗

Abstract

Summary

In 24 rats the left ovary was transplanted to the spleen, and between 40 and 50 days later they were permitted to become pregnant. Six animals were sacrificed at the termination of pregnancy, and in all the intrasplenic ovary showed distinct proliferation of new follicles, and only one of these in addition contained a corpus luteum. Nine animals were sacrificed at intervals up to 60 days post partum, and in these the intrasplenic ovary showed progressive atrophy. In another series, the normal right ovary was removed at the termination of pregnancy and groups of 3 animals were sacrificed 10, 31, and 62 days later. The intrasplenic ovary of this series showed progressive enlargement with the continuous formation of new follicles and corpora lutea, and there was no evidence of involution of the latter. In this experiment, the gonadotrophic hormones of pregnant rats produced primarily follicular activity in the intrasplenic ovary, while simultaneously in the normally situated ovary corpora lutea were formed and maintained.