Prostaglandins, possible mediators of the effects of oestrogens on luteinizing hormone output

A possible mechanism for the positive and negative feed-back effects of oestrogen on luteinizing hormone (LH) output is suggested. It is proposed that oestrogens may influence prostaglandin synthesis in the hypothalamus in relation to LH releasing hormone (LH.RH) synthesis and release. Changes in oestrogen level or in the oestrogen to progesterone ratio may alter the ratios of prostaglandin concentrations in the hypothalamus, and so modulate LH.RH output through effects on sympathetic neurotransmission, protein synthesis or LH.RH release.