ABSTRACT
Andrew V. Schally and Ana Maria Comaru-Schally Tulane University School of Medicine and Veterans Affairs Medical Center, New Orleans, Louisiana
I. INTRODUCTION
Various studies carried out in the 1960s and 1970s established that the secretion of growth hormone (GH) from the anterior pituitary gland is regulated by a dual system of hypothalamic control, and materials that could stimulate (13) or inhibit (3) the release of GH, were demonstrated in hypothalamic extracts. In 1970s the tetradecapeptide, which inhibits the release of GH and was named somatostatin, was isolated from ovine (4) and, subsequently, porcine hypothalami (5) and synthesized. The breakthrough on the identification of growth hormonereleasing hormone (GHRH) was provided by Frohman (6), who demonstrated ectopic production of GHRH by carcinoid and pancreatic cell tumors. In 1982, two groups isolated GHRH from human pancreatic tumors that caused acromegaly (7,8). Guillemin et al. reported a 44-amino acid amidated peptide [GHRH (I-44)NH2] (8) and Rivier et al. (7) a 40-amino acid peptide [GHRH (1-40)0H and GHRH(l-29)NH2]. Subsequently, GHRH(l-44)NH2 was isolated from human and animal hypothalami (9, 10). Virtually full intrinsic biological activity is present in the 29 NH2-terminal amino acid residues [GHRH(l-29)NH2] (7).
