Inhibin B

Function

Inhibin B is a glycoprotein hormone involved in reproductive endocrine regulation, gonadal feedback signaling, spermatogenesis-related communication, and control of follicle-stimulating hormone secretion. The hormone functions as an important feedback regulator within the hypothalamic-pituitary-gonadal axis and reflects activity of developing reproductive tissues.

In females, inhibin B is associated mainly with early and mid-follicular ovarian activity and contributes to regulation of follicle recruitment and maturation. In males, Sertoli-cell-derived inhibin B reflects spermatogenic activity and participates in communication between testicular tissue and pituitary endocrine pathways. Through these actions, inhibin B helps coordinate reproductive hormone balance and gonadal function.

Production

Inhibin B is produced by ovarian granulosa cells in females and Sertoli cells in males. In women, secretion is highest during the follicular phase when developing ovarian follicles actively communicate with pituitary endocrine pathways. In men, inhibin B production reflects Sertoli-cell activity and spermatogenesis-associated signaling.

The hormone consists of alpha and beta-B glycoprotein subunits that combine to form the active dimeric hormone. Production occurs under influence of gonadotropin stimulation and local reproductive tissue signaling pathways.

Regulation

Inhibin B production is regulated by follicle-stimulating hormone, gonadal maturation, reproductive-cycle timing, spermatogenic activity, and gonadal steroid signaling. Ovarian follicle recruitment and testicular Sertoli-cell function strongly influence secretion dynamics.

Inhibin B acts primarily on the anterior pituitary gland where it suppresses follicle-stimulating hormone synthesis and release through feedback mechanisms integrated with activin signaling systems. Interactions among gonadal tissues, pituitary gonadotropes, and hypothalamic reproductive pathways maintain endocrine reproductive coordination. Through these integrated feedback systems, inhibin B regulates reproductive endocrine balance, follicular signaling, and gonadal communication.