Control of Ovulation with Human Gonadotrophins

Abstract

It is through the two gonadotropins, the follicle stimulating hormone (FSH) and the luteinizing hormone (LH), that the anterior pituitary controls the timing of ovulation and the number of follicles that rupture. Under the influence of FSH, the follicular growth occurs at a constant rate for any given species (Hisaw, 1947). This rate cannot be accelerated by increasing the doses of exogenous FSH (Davis and Hellbaum, 1944). The number of follicles developing to maturity is also constant for each species but can be increased by the addition of exogenous FSH (Brambell, 1956). As each follicle seems to require a certain amount of FSH for maturation, the release of FSH from the anterior pituitary of each species may also be constant (Evans and Simpson, 1940). Thus, the amount of exogenous FSH needed for a normal ovarian response varies with different species. Too much or too little will cause too many or too few follicles to develop and mature.