Luteinizing hormone in the menstrual cycle

Luteinizing hormone acts together with follicle-stimulating hormone in the final stages of ovarian follicle maturation, stimulating the release of oestrogen from them. At low or constant levels of oestrogen the effect on LH release is negative. However, when oestrogen levels become high as the follicle approaches maturation positive feedback occurs; the anterior pituitary becomes more responsive to the effect of gonadotrophin releasing hormone and there is a peak in LH secretion. Ovulation occurs about nine hours after the peak is reached.

LH then goes on to promote formation of the corpus luteum - hence the name - and the secretion of progesterone in the second half of the menstrual cycle.

The high levels of oestrogen, progesterone and inhibin has a negative feedback effect on production of LH by the anterior pituitary during the second half of the menstrual cycle.