Characterization of serotonin and N-acetylserotonin systems in the human epidermis and skin cells.

ABSTRACT: Tryptophan hydroxylase (TPH) activity was detected in cultured epidermal melanocytes and dermal fibroblasts with respective Km of 5.08 and 2.83 mM and Vmax of 80.5 and 108.0 µmol/min. Low but detectable TPH activity was also seen in cultured epidermal keratinocytes. Serotonin and/or its metabolite and precursor to melatonin, N-acetylserotonin (NAS), were identified by LC/MS in human epidermis and serum. Endogenous epidermal levels were 113.18 ± 13.34 and 43.41 ± 12.45 ng/mg protein for serotonin (n = 8/8) and NAS (n = 10/13), respectively. Their production was independent of race, gender, and age. NAS was also detected in human serum (n = 13/13) at a concentration 2.44 ± 0.45 ng/mL, while corresponding serotonin levels were 295.33 ± 17.17 ng/mL (n = 13/13). While there were no differences

SUBMITTER: Slominski AT 

PROVIDER: S-EPMC7007327 | biostudies-literature | 2020 Mar

REPOSITORIES: biostudies-literature