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BIBTEX RIS

I. Melanin concentrating hormone exhibits both MSH and MCH activities on individual melanophores

1987; Elsevier BV; Volume: 40; Issue: 19 Linguagem: Inglês

10.1016/0024-3205(87)90041-5

1879-0631

Ana Maria de Lauro Castrucci, Mac E. Hadley, Brian C. Wilkes, Christian Zechel, Victor J. Hruby,

Regulation of Appetite and Obesity

AspThrMetArgCysMetValGlyArgValTyrArgProCysTrpGluVal (melanin concentrating hormone, MCH) and several fragment analogs (MCH1−14, MCH5−17, MCH5−14) were synthesized and their biological activities determined in a very sensitive fish skin bioassay. The potency ranking and minimum effective doses of the peptides were determined to be: MCH1−17 (10−12M) >< MCH5−17 (10−12M) > MCH1−14 (10−11M) > MCH5−14 (2 × 10−10M). The melanosome aggregating activity of MCH could be completely reversed by a 100-fold higher concentration of ≺-MSH. MCH was self-antagonized in a dose-related manner by higher concentrations of the peptide as was the activity of the MCH1−14 fragment analog. The MCH activities of the MCH5−17 and MCH5−14 analogs were not compromised by even the highest concentrations of the peptides employed. The MSH-like activity of MCH appears to relate to the N-terminus of the peptide whereas MCH activity is more a function of the C-terminus of the hormone. Self- antagonism of MCH at high concentrations appears to relate to the N-terminal tetrapeptide, which is responsible for the intrinsic MSH-like activity of the hormone.