ASSAY OF MELANOTROPIC PEPTIDES IN AN INVITRO MAMMALIAN SYSTEM

[摘要] A reproducible and sensitive assay for melanotropic agents is described employing mouse melanoma PSI-HGPRT-1 cells and measuring tyrosinase activity in terms of production of [3H] water from L-(ring-3,5-3H)-tyrosine. Molar concentrations of peptides inducing 1/2 maximal stimulation of tyrosinase activity were .beta.-MSH, 1 .+-. 2 .times. 10-9; .alpha.-MSH and .beta.h-LPH [lipotropin] 1 .+-. 2 .times. 10-8; porcine ACTH, 1 .+-. 2 .times. 10-7. Porcine .beta.9-18-MSH and melanotropin potentiating factor, .beta.s88-91-LPH, exhibited no activity at concentrations as high as 10-5 M.