Effects of progesterone, oestradiol-17 beta and androstenedione on follicular growth after removal of the corpus luteum during lactational and seasonal quiescence in the tammar wallaby.

The corpus luteum was removed from tammar wallabies during either lactational or seasonal quiescence, and the pouch young were replaced on the teat after lutectomy. Follicular development resumed and the animals came into oestrus 11-14 days later. Injections of oil, progesterone or androstenedione did not prevent follicular growth, although ovulation only occurred in one animal, but treatment with oestradiol-17 beta, either alone or mixed with progesterone, inhibited the development of follicles. These results suggest that oestrogen, of luteal origin, is responsible for the suppression of follicular development during lactational and seasonal quiescence.