Inhibin is a peptide that is an inhibitor of FSH synthesis and secretion and participates in the regulation of the menstrual cycle. An inhibitor is a type of effector (biology) that decreases or prevents a chemical reaction. ... Follicle stimulating hormone (FSH) is a hormone produced by gonadotropes in the anterior pituitary gland. ... Synthesis (from the Greek words syn = plus and thesis = position) is commonly understood to be an integration of two or more pre-existing elements which results in a new creation. ... Secretion is the process of segregating, elaborating, and releasing chemicals from a cell. ... The phrase menstrual cycle ( or period) refers to the recurring physiological changes in a females body that are under the control of the reproductive hormone system and necessary for reproduction. ...

Structure

Inhibin contains an alpha and beta subunit linked by disulfide bonds. Two forms of inhibin differ in their beta subunits (A or B), while their alpha subunits are identical. Inhibin belongs to the transforming growth factor-β (TGF-β) family. In chemistry, a disulfide is an ion formed by sulfur atoms. ...

Action

FSH stimulates the secretion of inhibin from the granulosa cells of the ovary. In turn, inhibin suppresses FSH. Inhibin secretion is diminished by GnRH, and enhanced by insulin-like growth factor-I. Inhibin B reaches a peak in the early-mid follicular phase, and a second peak at ovulation, in contrast to inhibin A that reaches its peak in the midluteal phase. Inhibin is produced in the gonads, pituitary gland, placenta and other organs. Cells in culture, stained for keratin The cell is the structural and functional unit of all living organisms. ... Human female internal reproductive anatomy Ovaries are a part of a female organism that produces eggs. ... Gonadotropin Releasing Hormone (GnRH) is a peptide hormone responsible for the release of FSH and LH from the anterior pituitary. ... The insulin-like growth factors (IGFs) are polypeptides with high sequence similarity to insulin. ... The phrase menstrual cycle ( or period) refers to the recurring physiological changes in a females body that are under the control of the reproductive hormone system and necessary for reproduction. ... Ovulation is the process of discharging a mature ovum (egg) from an ovary after a Graafian follicle - representing the final stage of follicular development before ovulation - has been formed. ... The phrase menstrual cycle ( or period) refers to the recurring physiological changes in a females body that are under the control of the reproductive hormone system and necessary for reproduction. ... A sex organ, or primary sexual characteristic, narrowly defined, is any of those parts of the body (which are not always bodily organs according to the strict definition) which are involved in sexual reproduction and constitute the reproductive system in an complex organism; namely: Male: penis (notably the glans penis... Located at the base of the skull, the pituitary gland is protected by a bony structure called the sella turcica. ... Human placenta shown a few minutes after birth. ...

Activin

Activin is a related peptide that counteracts inhibin. Activin is a peptide that enhances FSH synthesis and secretion and participates in the regulation of the menstrual cycle. ...