Inhibin A | Laboratory research

General Information

Inhibins are hormones of the reproductive system that are involved in the development of oocytes (ovum precursor cells). In women, inhibins are produced mainly by the granulosa cells of the ovary, during pregnancy - by the placenta. Their amounts are different in different phases of the ovary. Inhibin A levels are low in the early follicular phase, increase during ovulation, and reach a maximum in the midluteal phase. Inhibin B, on the contrary, is high in the follicular phase and then decreases.

Inhibin selectively inhibits the secretion of FSH by the pituitary gland (based on the principle of negative feedback), regulates folliculogenesis and spermatogenesis, has a local paracrine effect on the gonads. Inhibin synthesis reduces gonadoliberin secretion; Androgens, FSH and insulin-like growth factor-1 increase its secretion.

Inhibin A is used to diagnose and monitor the treatment of ovarian granulosa cell tumors, and sometimes mucinous, epithelial tumors. However, in some of the confirmed cases of these tumors, there is no increase in the amount of inhibin A (or B).

Inhibin levels are high during premenopause, corresponding to the phases of the cycle.

In boys, the level of inhibin increases during childhood, the peak of concentration is at 3 months, which is accompanied by a gradual decline by the age of 10. Detection of inhibin indicates the presence and functional ability of testicular tissues, and is used to determine the sex in suspicious situations and pathologies in the development of the gonads.

Analysis of this hormone allows us to distinguish between anorexia (congenital absence of testicles) and cryptorchidism (testicles are not present in the testis) in order to timely prescribe the necessary treatment.