Motilin

Literature References: A gastrointestinal peptide hormone whose existence was postulated during experimental chemical stimulation of canine duodenum: J. C. Brown et al., Gastroenterology 50, 333 (1966). Motilin stimulates gastric antrum, duodenum, and colon; it has been reported to be about 50 times more powerful than acetylcholine in its effects on sensitive tissue: U. Strunz et al., ibid. 68, 1485 (1975). In man it is found primarily in the upper small intestine. Although its effects are not known completely, it plays a role in increasing gastric motility and stimulating pepsin output and may also be important in regulating the interdigestive myoelectric complex. Porcine motilin, which contains 22 amino acids, has been isolated from mucosa of hog small intestine: J. C. Brown et al., Can. J. Physiol. Pharmacol. 49, 399 (1971). Purification, amino acid composition, C-terminal residue: eidem, Gastroenterology 62, 401 (1972). Amino acid sequence: eidem, Can. J. Biochem. 51, 533 (1973); revised sequence: H. Schubert, J. C. Brown, ibid. 52, 7 (1974). First synthetic work: E. Wünsch et al., Z. Naturforsch. 28C, 235 (1973). Synthesis of the complete docosapeptide corresponding to porcine motilin: H. Yajima et al., Chem. Commun. 1975, 159. Alternate syntheses: Y. Kai et al., Chem. Pharm. Bull. 23, 2346 (1975); S. Yamada et al., J. Am. Chem. Soc. 97, 7174 (1975); E. Izeboud, H. C. Beyerman, Rec. Trav. Chim. 99, 124 (1980). Solid phase synthesis: N. Ikota et al., Chem. Pharm. Bull. 28, 3347 (1980); D. H. Coy et al., Peptides 3, 137 (1982). Radioimmunoassay: J. R. Dryburgh, J. C. Brown, Gastroenterology 68, 1169 (1975). Identification of motilin endocrine cells: J. M. Polak et al., Gut 16, 225 (1975). Rodent and canine motilin differ from porcine; human motilin has not yet been purified, although its immunologic properties suggest strong similarity to porcine motilin. The presence of a larger motilin has also been detected immunologically, see J. M. Polak, A. M. J. Buchan, Gastroenterology 76, 1065 (1979). Reviews: N. D. Christofides et al., "Physiology of Motilin" in Gut Hormones, S. R. Bloom, Ed. (Churchill Livingstone, Edinburgh, 1978) pp 343-350; S. R. Bloom, J. M. Polak, Clin. Endocrinol. Metab. 8, 401-411 (1979); V. Mutt, Vitam. Horm. 39, 231-426 (1982).