Abstract
The present study was undertaken in order to examine whether ceruloplasmin, tyrosinase and AgNO3 change 5-HT into the pigment in vitro. The effects of 2, 3-Dimercaptopropanol (BAL) and α-MSH on the pigment formation from 5-HT was also studied. As a comparative study, the pigment formation from noradrenaline was also studied. 1) When noradrenaline was incubated with tyrosinase, the browish black pigment was formed. BAL inhibited this pigment formation, but α-MSH did not affect it. 2) The incubation of 5-HT with tyrosinase, α-MSH, or with both of them did not produce the pigment. 3) When 5-HT was incubated with AgNO3 or with ceruloplasmin, the brown or the brownish black pigment was formed from 5-HT respectively. BAL inhibited the both types of pigment formation from 5-HT. α-MSH had no effect on the pigment formation from 5-HT by ceruloplasmin.