title: The effects of pro-opiomelanocortin peptides on cyclic AMP and tyrosinase in melanoma cells.
abstract: Des-, mono-, and diacetylated melanotropin (des-, mono-, and di-Ac MSH, respectively) were compared for their dose-related effects on content of adenosine 3':5'-monophosphate (cAMP) and tyrosinase activity in the Cloudman S91 mouse melanoma tumor. Des-Ac MSH was more potent than the acetylated forms of MSH at increasing cellular levels of cAMP; mono- and di-Ac MSHs, however, were more potent than des-Ac MSH at elevating the activity of the enzyme, tyrosinase. Lysine-gamma1 MSH, a melanotropin from the amino terminus of pro-opiomelanocortin, exhibited slight stimulatory effects on tyrosinase and these actions were less than additive to those of mono-Ac MSH. Unlike their actions on amphibian skin-darkening or in mammalian behavior, neither beta-endorphin1-31 nor its derivatives, N-Ac-beta-endorphin1-27 or beta-endorphin30-31 (glycylglutamine), exhibited any influence on tyrosinase activity evoked by mono-Ac MSH in the tumor cells.
mesh_terms: D000818:Animals; D004156:Catechol Oxidase / Q000378:metabolism*; D000242:Cyclic AMP / Q000378:metabolism*; D007700:Kinetics; D009074:Melanocyte-Stimulating Hormones / Q000494:pharmacology; D008546:Melanoma, Experimental / Q000378:metabolism*; D051379:Mice; D014442:Monophenol Monooxygenase / Q000378:metabolism*; D011333:Pro-Opiomelanocortin / Q000031:analogs & derivatives* / Q000494:pharmacology*; D013329:Structure-Activity Relationship
chemical_list: D011333:Pro-Opiomelanocortin; D009074:Melanocyte-Stimulating Hormones; D000242:Cyclic AMP; D004156:Catechol Oxidase; D014442:Monophenol Monooxygenase