Induction of Ovo-Implantation in Rats by Luteinized and Follicle Containing Ovarian Grafts

Abstract

The pregnant rat, in which implantation had been delayed by ovariectomy and progesterone administration, was used to determine the structural component of the ovary that may be responsible for the estrogen secretion that presumably causes implantation. Autografts and homografts of luteinized follicular tissue were made to the kidney capsule at the time of ovariectomy. Both types of tissue caused implantation of blasto-cysts. Follicular grafts induced implantation about one day later than it normally occurs in the intact rat and 2-3 days earlier thanluteal grafts. Corpora lutea transplants from 14 day pregnant rats or ovarian grafts from immature rats were as effective in causing implantation as the pregnant host rat''s own ovarian tissue. It is concluded that corpora lutea are able to secrete estrogen and may be the normal source of estrogen at the time of implantation.