Effect of corpora lutea grafted under renal capsule on pregnancy in the rabbit

Implantation of the blastocyst and maintenance of pregnancy were examined by autografting corpora lutea under renal capsule in rabbits. Implantation of the blastocyst did not occur when the corpora lutea were autografted because of small amounts of lutein tissue, low secretory activity of lutein cells, and the period required for functional activity of grafts. Autografts of 4-day-old corpora lutea were capable of maintaining pregnancy after 15 days post coitum, when follicles and interstitial tissue remained intact. Pregnancy was maintained in a limited number of fetuses when 6-day-old corpora lutea were autografted in ovariectomized estradiol-treated does.