QS Study


It is a polypeptide hormone secreted from grafian follicle of the ovary. It is also involved in the control of the production of gametes and embryonic and fetal development.

Structure: It contains 3 polypeptide subunits:- one α and 2 β subunits.

  • Inhibin A = β + βA (α β A)
  • Inhibin B = α + β B (α β B)

Inhibin A and inhibin B have dissimilar patterns of movement during the two phases of the ovarian cycle and play diverse physiological roles during follicular enrollment, maturation, and ovulation.

During pregnancy, the placenta secretes inhibin A, and the fetal membranes secrete inhibin A and inhibin B, but for at least the first 20 weeks of gestation, only inhibin A is detected in maternal serum.

Function: It inhibits the secretion of FSH. It is a glycoprotein hormone that is secreted by the pituitary gland and in the male by the Sertoli cells and in the female by the granulosa cells and that inhibits the secretion of the follicle-stimulating hormone. For medical purposes, measurement of inhibins in the movement is a consistent indicator for some types of ovarian cancer, and also a predictor for the conditions of spermatogenesis.

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