Aspects of current and future inhibin research.

Inhibin was first isolated in 1985. Major progress has been made in defining various aspects of its structure and physiology, using a heterologous radioimmunoassay. Current research is aimed at characterizing the nature of the circulating forms of inhibin and is examining whether there are sex-specific roles for inhibins A and B. It has been recognized that various forms of epithelial and stromal ovarian cancer produce members of the inhibin peptide family but the precise nature of these products is not yet clear. The recognition that the inhibin subunits together with follistatin are expressed locally within the pituitary has lead to an investigation of their possible roles in intrapituitary regulation. It is clear that these peptides also have intragonadal roles. Of particular current interest is the nature of the signals that control the specificity of cellular peptide production and that determine whether a particular cell produces inhibin or activin. The inhibins are members of a complex family with many potential roles in physiology and pathophysiology. The role of the inhibins in feedback control of follicle stimulating hormone in the male, particularly, remains unclear. New applications for inhibin and related peptides are likely to be developed.