gonadotropin /gō′nədōtrop″in/ [Gk, gone + trophe, nourishment] , a hormonal substance that stimulates the function of the testes and the ovaries. The gonadotropic follicle-stimulating hormone and luteinizing hormone are produced and secreted by the anterior pituitary gland. In early pregnancy, human chorionic gonadotropin is produced by the placenta (basis for early pregnancy detection). It acts to sustain the function of the corpus luteum of the ovary, forestalling menstruation and thus maintaining pregnancy. Gonadotropins are prescribed to induce ovulation in infertility that is caused by inadequate stimulation of the ovary by endogenous gonadotropic hormones. Excessive stimulation of the ovary may result in vast enlargement of the gland, maturation of many follicles, multiple pregnancy, bleeding into the abdomen, and pain. While named for their effects on the ovaries, follicle-stimulating hormone and luteinizing hormone are also major gonadotropins in the testes, causing the Leydig cells to secrete testosterone and facilitating spermatogenesis. Also called gonadotrophin. −gonadotrophic, gonadotropic, adj.
