Parathyroid Hormone

Literature References: Regulatory factor in the homeostatic control of calcium and phosphate metabolism, its principal sites of activity being the skeleton, kidneys, and gastrointestinal tract. Prime function is to raise plasma calcium concns. Acts synergistically with vitamin D3, q.v. except in the kidneys where the latter causes phosphate retention. Secretion from the parathyroid gland varies inversely with serum Ca2+ concentrations, unlike calcitonin, q.v., which is secreted in direct proportion to serum calcium levels. Structure consists of a single-chain polypeptide of 84 amino acid residues. Sequence varies slightly among mammalian species. Sequence of bovine PTH: Niall et al., Z. Physiol. Chem. 351, 1586 (1970); Brewer, Ronan, Proc. Natl. Acad. Sci. USA 67, 1862 (1970). Sequence of porcine PTH: O'Riordan et al., Proc. R. Soc. Med. 64, 1263 (1971). Isoln of human PTH from parathyroid adenomas: O'Riordan et al., Endocrinology 89, 234 (1971). Fragment exhibiting full biological activity consists of about 35 amino acid residues from the N-terminal: Potts et al. in Parathyroid Hormone and Thyrocalcitonin (Calcitonin), R. V. Talmage, L. F. Belanger, Eds. (Excerpta Medica, New York, 1968) p 44; see in entirety for review and special studies. Synthesis of active bovine fragment: Potts et al., Proc. Natl. Acad. Sci. USA 68, 63 (1971); of human PTH (1-38): S. Funakoshi et al., Pept. Chem. 18, 223 (1980). Reviews of early literature: Potts et al., Recent Prog. Horm. Res. 22, 101 (1966); Arnaud et al., Annu. Rev. Physiol. 29, 349 (1967). Reviews: Behrens, Grinnan, Annu. Rev. Biochem. 38, 83 (1969); Auerbach et al., Recent Prog. Horm. Res. 28, 353 (1972); Parsons, Potts, "Physiology and Chemistry of Parathyroid Hormone" in Clinics in Endocrinology and Metabolism I. MacIntyre, Ed. (Saunders, Philadelphia, 1972) pp 33-78. Biosynthetic review: J. F. Habener et al., Recent Prog. Horm. Res. 33, 249 (1977).