*10.1.1 Luteinizing hormone*

In both sexes, LH stimulates secretion of sex steroids from the gonads. In the testes, LH binds to receptors on Leydig cells, stimulating synthesis and secretion of testosterone. Theca cells in the ovary respond to LH stimulation by secretion of testosterone, which is converted into estrogen by adjacent granulosa cells. In females, the LH surge leads to ovulation of mature follicles on the ovary and later to form corpus luteum, which secrete the steroid hormones progesterone and oestradiol. In the event of pregnancy progesterone is necessary for the maintenance of that pregnancy.
