Abstract: Objective To study the effects of endothelin-1 (ET-1) and adrenocorticotropic hormone (ACTH) on the proliferation of cultured normal human melanocytes.Methods Normal human melanocytes were obtained from the foreskins of healthy men,and cultured in minimum essential medium (MEM) with 10% bovine serum.The cultured melanocytes of the 3rd passage were treated with various concentrations of ET-1 and ACTH.Cell proliferation was assessed by the MTT method.Results ET-1 (0.1~1 000 nmol/L) promoted the proliferation of cultured human melanocytes.ACTH (10^-13~10^-9 mol/L) also promoted the proliferation of cultured human melanocytes (P<0.05),with 10^-9 mol/L being the most efficient concentration.There was no significant difference in the effect of ACTH at the concentrations of 10^-12 mol/L,10^-11 mol/L and 10^-10 mol/L.Conclusions ET-1 and ACTH could promote the proliferation of melanocytes,which occurs even at low concentrations of ET-1.ACTH,at physiological (10^-12 and 10^-11 mol/L) or higher concentrations could also promote the proliferation of melanocytes.Therefore,these two factors might be utilized in non-carcinogen culture and transplantation of melanocytes as well as direct treatment of vitiligo in the future.

Key words: Melanocyte, Endothelin-1, Corticotropin