Hearnshaw H, Cuming I A, Goding J R
Aust J Biol Sci. 1977 Jun;30(3):217-23. doi: 10.1071/bi9770217.
Luteinizing hormone (LH) concentration was measured in the jugular plasma of six groups of ovariectomized ewes which were fed oestrogenic clover (Trifolium subterranean L. Gray cv. Yarloop) for 3 days. Ewes in groups B, D and F received an injection of oestradiol-17beta (E2) 24 h after first being offered clover, whilst ewes in groups A, C and E received no oestrogen treatment. Following the initial ingestion of clover, plasma LH concentrations for all groups fell within 3 h and then increased significantly. Each subsequent feeding of clover usually resulted in a temporary decrease and then an elevation of the LH concentrations. When ewes in groups B, D and F were injected with E2, LH concentrations fell and remained low for approximately 9 h, then increased to a peak of 72-3 +/- 10-4 ng/ml within 5 h. The LH concentrations remained elevated for a period of about 12 h. The present paper indicates that the ingestion of oestrogenic clover by ovariectomized ewes results in a depression and then a release of LH, and that this release does not appear to deplete the pituitary of LH or cause refractoriness to an oestrogenic stimulus.
对六组切除卵巢的母羊的颈静脉血浆中的促黄体生成素（LH）浓度进行了测定，这些母羊喂食含有雌激素的三叶草（地下三叶草，Trifolium subterranean L. Gray cv. Yarloop）3天。B组、D组和F组的母羊在首次喂食三叶草24小时后注射了17β-雌二醇（E2），而A组、C组和E组的母羊未接受雌激素处理。在首次摄入三叶草后，所有组的血浆LH浓度在3小时内下降，然后显著升高。随后每次喂食三叶草通常都会导致LH浓度暂时下降，然后升高。当B组、D组和F组的母羊注射E2时，LH浓度下降并在约9小时内保持在低水平，然后在5小时内升至72 - 3 +/- 10 - 4 ng/ml的峰值。LH浓度在约12小时内保持升高。本文表明，切除卵巢的母羊摄入含有雌激素的三叶草会导致LH的抑制然后释放，并且这种释放似乎不会耗尽垂体中的LH或导致对雌激素刺激产生不应性。
