The effect of age and hair colour on human hairbulb tyrosinase activity.

We studied tyrosinase activity from human hairbulbs from 51 subjects, aged 5-72 years. We used anagen hairbulbs and grouped the subjects according to hair colour. We did not observe an age-dependent fall in hairbulb tyrosinase activity. We observed considerable inter-individual variation in activity, with a range of 8-342 pmol DOPA formed/three hairbulbs/30 min. The mean tyrosinase activity from red hairbulbs was significantly higher than the mean for the other hair colours. White hairbulbs did not express tyrosinase activity, and specific antibodies to tyrosinase were used to establish that tyrosinase antigen was absent from white hairbulbs.