Müllerianinhibiting

Müllerian inhibiting substance, also known as Müllerian inhibiting factor (MIF) or anti-Müllerian hormone (AMH), is a glycoprotein hormone of the transforming growth factor-beta superfamily. In humans and other mammals, it plays a crucial role during sexual differentiation in utero. During typical male development, AMH is produced by Sertoli cells in the developing testes. Its primary function is to cause the regression of the Müllerian ducts, which are embryonic structures that would otherwise develop into the female reproductive organs, namely the uterus, fallopian tubes, and the upper part of the vagina. Simultaneously, the Wolffian ducts develop into the male reproductive structures, such as the epididymis, vas deferens, and seminal vesicles, under the influence of androgens like testosterone.

In females, where AMH is produced by granulosa cells in the developing ovaries, the Müllerian ducts are allowed to persist and develop into the female reproductive tract. The Wolffian ducts, in the absence of significant androgenic stimulation, typically regress. After birth, AMH levels in males remain relatively high during childhood and decline significantly after puberty. In females, AMH levels rise during puberty and then gradually decline with age, eventually becoming undetectable after menopause.

Beyond its role in fetal development, AMH has significance in reproductive health throughout life. In women, AMH levels are used as an indicator of ovarian reserve, reflecting the number of remaining small follicles. In men, mutations in the AMH gene or its receptor can lead to persistent Müllerian duct syndrome, a rare disorder where both male and female reproductive structures are present.