Description

Inhibin A is a protein hormone produced by the ovaries in females and the testes in males. It is one of the subtypes of inhibin, a hormone that plays a role in the regulation of the reproductive system by inhibiting the secretion of follicle-stimulating hormone (FSH) from the pituitary gland.

In females, inhibin A is primarily produced by the granulosa cells of the ovarian follicles. Its secretion is highest during the early to mid-follicular phase of the menstrual cycle, coinciding with follicular development. Inhibin A levels gradually decrease as the dominant follicle matures and ovulation approaches. Inhibin A levels also rise during pregnancy, with peak levels occurring in the second trimester.

In males, inhibin A is produced by Sertoli cells within the seminiferous tubules of the testes. It helps regulate the production of sperm by inhibiting FSH secretion from the pituitary gland. Inhibin A levels in males are relatively stable and do not fluctuate as markedly as in females.

Measurement of inhibin A levels in blood or serum can be used as a marker of ovarian function in females and testicular function in males. In females, abnormal levels of inhibin A may be associated with conditions such as polycystic ovary syndrome (PCOS), ovarian tumors, or ovarian dysfunction. In males, abnormal levels of inhibin A may be associated with testicular tumors or disorders affecting spermatogenesis.

Inhibin A levels are often measured in conjunction with other reproductive hormones, such as FSH, luteinizing hormone (LH), estradiol (E2) in females, and testosterone in males, to assess overall reproductive health and function. The interpretation of inhibin A levels should be done in the context of the individual’s clinical history, symptoms, and other laboratory findings.