Sex Hormones

SEX HORMONES, a group of hormones that influence the development and function of the primary and secondary sexual characteristics of an organism. Their isolation is hardly complete, just as a precise scheme of their interrelationships cannot be considered established. The mechanism of their action in different animal species is not entirely identical. Sex hormones include hormones isolated from the anterior lobe of the pituitary gland and from the urine and blood of pregnant females—prolan (see) A and B (Zondek and Aschheim). The male sex hormone, in addition to the testes, has been found in the blood and urine of males and in smaller quantities in females. Its exact chemical structure is unknown. The male sex hormone causes the growth of the comb and specific plumage in castrated roosters, and the proliferation of the seminal vesicles and prostate in rodents. The female sex hormone—folliculin—has been isolated in a chemically pure form in several forms of varying degrees of activity. It is found in follicular fluid, in the blood and urine of non-pregnant females, and in enormous quantities in pregnant females in the placenta, fetal membranes, and fluid; it is found in small quantities in the blood and urine of males, and also in certain plants. The hormone of the corpus luteum is progestin. The following actions of it have been described: 1) enhancement of endometrial hyperplasia caused by folliculin, and preparation of the uterine mucous membrane for the implantation of the egg; 2) changes in the vaginal mucosa characteristic of pregnancy; 3) weakening of the rhythmic contractions of the uterus; 4) neutralization of the action of folliculin and the hormone of the posterior lobe of the pituitary gland on uterine contractions; 5) neutralization of the action of prolan A and prevention of ovulation; 6) prolongation of the term of pregnancy; 7) cessation of menses and metrorrhagia caused by folliculus persistens. (See also Ovulation.) There are also numerous clinical data indicating the influence of the adrenal cortex on sexual characteristics, although there are no reliable laboratory-experimental data as yet. The question of the hormonal activity of the uterus is also not resolved. Despite the precisely determined structure of some sex hormones and highly sensitive biological tests that allow for the determination of the exact dosage of sex hormones, their use for therapeutic purposes in humans has not yet led to entirely successful results. Sex hormones are beginning to acquire very important significance in animal husbandry and fur farming, allowing for the modification of the sexual cycle of animals depending on the goals and needs of the farm.