<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>testicular peptide hormone which inhibits pituitary secretion of FSH; same name has been used for a TUMOR SUPPRESSOR PROTEIN, do not confuse.</n0:def-definition><n0:def-source>CSP2002</n0:def-source></n0:ComplexDefinition><n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>Glycoproteins that inhibit pituitary FOLLICLE STIMULATING HORMONE secretion. Inhibins are secreted by the Sertoli cells of the testes, the granulosa cells of the ovarian follicles, the placenta, and other tissues. Inhibins and ACTIVINS are modulators of FOLLICLE STIMULATING HORMONE secretions; both groups belong to the TGF-beta superfamily, as the TRANSFORMING GROWTH FACTOR BETA. Inhibins consist of a disulfide-linked heterodimer with a unique alpha linked to either a beta A or a beta B subunit to form inhibin A or inhibin B, respectively</n0:def-definition><n0:def-source>MSH2002_06_01</n0:def-source></n0:ComplexDefinition>
<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>Inhibins are peptide hormones, secreted by the follicular cells of the ovary and by the testis, that negatively regulate the synthesis and secretion of follicle stimulating hormone from the anterior pituitary. The detection of serum inhibins has been implicated in association with reproductive disorders, including infertility and ovarian cancers.</n0:def-definition><n0:def-source>NCI</n0:def-source></n0:ComplexDefinition>
nci:P98
Both inhibin A and inhibin B are heterodimers consisting of an alpha subunit and a beta A or beta B subunit linked by disulphide bonds. Both inhibins function as negative regulators for FSH synthesis and secretion. Furthermore, serum concentrations of inhibins transit from inhibin B to inhibin A dominance during menstrual cycle.