Q.What is the role-played by luteinizing hormones in males and females respectively?

Luteinizing hormone, or LH, is one of the two gonadotrophins made by the anterior pituitary (the pars distalis), alongside its partner FSH. Like every hormone, LH acts only on its target tissue -- in this case the gonads, the testis in males and the ovary in females -- and what it actually does there is quite different in the two sexes.

In males, LH acts on the Leydig cells (the interstitial cells) of the testis and stimulates them to make and secrete androgens, chiefly testosterone. It does not itself drive sperm formation directly; instead it works upstream, switching on the hormone supply (androgens) that FSH then needs alongside it to carry out spermatogenesis.

In females, LH's role changes across the menstrual cycle. First it triggers ovulation -- the release of the egg from a fully ripe (graafian) follicle. Once ovulation has happened, LH then maintains the corpus luteum, the structure that forms from the ruptured follicle's remnants, which goes on to secrete progesterone. …