Oestrogen Excretion by Sows with Induced Cystic Ovarian Follicles

Abstract

Large multiple cystic ovarian follicles were induced in 5 sows and small multiple cystic ovarian follicles were induced in one sow by injections of adrenocorticotrophic hormone (ACTH) during the follicular phase of the oestrous cycle. Oestrogen excretion by sows with large cystic follicles was relatively high, while that from the sow with small cystic follicles was low. Cystic follicles in all sows underwent atresia about day 15 of the cycle and new follicular growth occurred in sows that had large cysts. Attempts to prevent atresia of the cysts with injections of ACTH failed in 2 sows. The results of administration of ACTH to an adrenalectomized sow suggest that the induction of cystic ovaries by ACTH is mediated through the adrenal cortex. A relative deficiency of ovulating hormone appears to occur, for ovulation was obtained when gonadotrophin was given during treatment with ACTH.