In the present study the role of progesterone and oestradiol in modulating the responsiveness at the anterior pituitary gland to gonadotrophin releasing hormone (GN-RH) was investigated by measuring the release of luteinizing hormone (LH) in ovariectomised mice which had been pretreated with these steroids. A significant release of LH was seen in the animals receiving GN-RH. Pretreatment with oestrogen and progesterone depressed LH levels in the animals which did not receive GN-RH, and resulted in a larger release of LH in the animals receiving GN-RH in comparison with the control group pretreated with oil.
Scandinavian Journal of Laboratory Animal Sciences, Vol. 14 No. 3 (1987)