Excretion of 5-S-cysteinyldopa in the urine of healthy subjects.

Seventy-six Caucasians, 30 men and 46 women, were investigated for the 24-hour excretion of 5-S-cysteinyl dopa in the urine during the months of September to November, 1973. No subject had had strong sun exposure for at least 4 weeks prior. A preliminary finding of a variation of 5-S-cysteinyldopa with season necessitated this precaution. The excretion varied between 9.0 and 242 mug/24 hours. The mean value in men was 100 mug/24 hours and in women 77.8 mug/24 hours. Subjects with white hair had lower values than those with pigmented hair, but there was no other difference between the excreted amounts in subjects with differing hair colour. There was no variation with age when the subjects with white hair were excluded. No variation with weight or body surface was found. Excretion of dopa and dopamine determined together did not correlate with the excretion of 5-S-cysteinyldopa.