What are inhibin A and B?
Inhibin A and inhibin B are hormones associated with reproduction and the development of oocytes (immature egg cells) in women’s ovaries. In women, these hormones are made mostly by the ovaries and by the placenta during pregnancy. Additionally, inhibin A and/or B may be produced by certain types of ovarian tumors.
What is the function of inhibin A?
Inhibin is a protein secreted by the Sertoli cells in men and by the granulosa cells in women. It inhibits the synthesis and release of the follicle-stimulating hormone in the pituitary gland and reduces the hypothalamic LH – releasing hormone content.
What is the role of inhibin B?
Inhibin B is involved in regulatory functions in developing follicles and seems to be a sensitive marker of ovarian follicle development.
What does high inhibin B mean?
The amount of inhibin B measured in serum during the early follicular phase of the menstrual cycle (day 3) directly reflects the number of follicles in the ovary. Therefore, the higher the inhibin B, the more ovarian follicles present.
What does inhibin B do in females?
Inhibin B is secreted by antral follicles in response to FSH, and is the major marker of follicular growth. Thus, inhibin B level is a marker of ovarian function, which may become a useful tool to identify the potential ovarian responsiveness to ovulation induction.
What does high inhibin A mean?
Conclusions. High levels of maternal serum inhibin-A in the second trimester are significantly associated with abnormal placentation, which increases the risk of preeclampsia and FGR with a consequence of indicated preterm birth but not a risk of spontaneous preterm birth.
Where is inhibin A produced?
Inhibin is produced in the gonads, pituitary gland, placenta, corpus luteum and other organs. FSH stimulates the secretion of inhibin from the granulosa cells of the ovarian follicles in the ovaries. In turn, inhibin suppresses FSH.
What if inhibin A is high?
What causes high inhibin A in pregnancy?
The level of elevated Inhibin A in pregnancy is significantly related to the outcome of pre-eclampsia, GDM, macrosomia, low birth weight and preterm delivery.
What does a low inhibin B mean?
79. The measurement may be useful in assessing reproductive aging because a low level of inhibin B on day 3 may indicate a declining ovarian reserve. 78. In men, inhibin B is produced by Sertoli cells and has been considered a good marker of spermatogenesis.
What happens when inhibin A is high?
Elevated Inhibin A levels in pregnancy are significantly associated with pre-eclampsia, GDM, macrosomia, low birth weight and preterm delivery.
What is inhibin a tumor marker?
Functional inhibin is secreted by all granulosa cell tumours of the ovary studied and can be used as a tumour marker to determine response to therapy and predict recurrence and is superior to oestradiol.
What type of hormone is inhibin A and B?
dimeric protein hormones
Inhibin A and inhibin B are related dimeric protein hormones and endocrine regulators of the reproductive axis. Specifically, inhibin inhibits FSH secretion from the anterior pituitary. The inhibins are synthesized by the gonads and are themselves modulated by FSH.