title: Des-acetyl MSH and gamma-MSH act as partial agonists to alpha-MSH on the Anolis melanophore.
abstract: The biological activities of alpha-MSH des-acetyl MSH, gamma-MSH and LPH37-58 were compared using the Anolis rate method of bioassay. Dose-response data showed LPH37-58 to be equipotent with alpha-MSH, but des-acetyl MSH and gamma-MSH were found to be much less active. The effect of LPH37-58 was additive to that of alpha-MSH, indicating that LPH37-58 is a full agonist of alpha-MSH. The lower potency peptides des-acetyl MSH and gamma-MSH reduced the effect of alpha-MSH and are, therefore, partial agonists of alpha-MSH. The action of MSH peptides in vivo may be modulated by interaction with agonists.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001681:Biological Assay; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D008116:Lizards; D009074:Melanocyte-Stimulating Hormones / Q000031:analogs & derivatives* / Q000494:pharmacology*; D008547:Melanophores / Q000187:drug effects*; D010446:Peptide Fragments / Q000494:pharmacology; D012867:Skin / Q000187:drug effects; D000521:alpha-MSH / Q000031:analogs & derivatives*; D008083:beta-Lipotropin / Q000494:pharmacology
chemical_list: D010446:Peptide Fragments; D000521:alpha-MSH; D009074:Melanocyte-Stimulating Hormones; D008083:beta-Lipotropin