1. Symbols and abbreviations are in accord with the recommendations of the IUPAC–IUB Commission on Biochemical Nomenclature (J. Biol. Chem. 1972, 247, 977). Other abbreviations include a-MSH: a-melanotropin, a-melanocyte-stimulating hormone; ß-MSH: ß-melanotropin; ?-MSH: ?-melanotropin; ACTH: adrenal corticotropin hormone; Nle: norleucine; 2,4-Cl2-Z: 2,4-dichlorobenzyloxycarbonyl; p-MBHA resin: p-methylbenzhydrylamine resin; HOBT: N-hydroxybenzotriazole; For: formyl; Tos: tosyl; Na-Boc: Na- tert-butyloxycarbonyl; 2,6-Cl2-Bzl: 2,6-dichlorobenzyl; CTAF: chlorotriazinylaminofluorescein. All optically active amino acids are of the L-variety unless otherwise stated.
2. The opiomelanotropinergic neuronal and endocrine systems