Details

Autor(en) / Beteiligte

• DePaolo, Louis V.
• Bicsak, Thomas A.
• Erickson, Gregory F.
• Shimasaki, Shunichi
• Ling, Nicholas

Titel

Follistatin and Activin: A Potential Intrinsic Regulatory System within Diverse Tissues

Ist Teil von

• Proceedings of the Society for Experimental Biology and Medicine, 1991-10, Vol.198 (1), p.500-512

Ort / Verlag

London, England: SAGE Publications

Erscheinungsjahr

1991

Quelle

MEDLINE

Beschreibungen/Notizen

• Until the 1920s, it was assumed that the sole gonadal hormones modulating anterior pituitary glandular secretions were lipid-soluble entities called steroids. Experimental evidence then surfaced during the ensuing decade that demonstrated that the testis also contained a hydrophilic material that might also influence pituitary secretory activity (1, 2). The name “inhibin” was given to this novel substance in view of its ability to inhibit hypertrophy of pituitary cells in castrated rats (2). Work in later years evoked the concept that inhibin could be an important regulator of follicle-stimulating hormone (FSH) secretion (3, 4). Thus, as a consequence of these landmark studies, investigators began a search to elucidate the chemical nature of the inhibins. Although inhibin was discovered as a potential secretory product of the testis, it was almost 45 years later that a nonsteroidal FSH suppressor was demonstrated in the ovarian follicular fluid of cows (5). Ironically, it was the ovarian follicular fluid from which chemists eventually isolated what was most likely the putative inhibin molecule described in the 1920s and 30s (6–9). Chemical characterization of the purified FSH-suppressing material revealed that inhibin is a 31-to 32-kDa heterodimer consisting of two distinct polypeptide chains, α and β. In pig follicular fluid, two inhibin heterodimers, A and B, were isolated and found to consist of a common α-subunit chain linked by disulphide bridges to a βA- or βB-subunit chain, respectively. Both inhibins were essentially equipotent in suppressing FSH secretion in the dispersed anterior pituitary cell bioassay system (6). At long last, the elusive inhibin had been proven a true chemical entity—a major breakthrough in reproductive endocrinology. However, little did anyone know that the gonads produced other FSH-regulatory polypeptide factors besides inhibin, and that the ability of these other factors to modulate FSH secretion could be only the tip of the iceberg with regard to the multi-functional properties of these factors, thereby extending their importance to other areas of biology.