D-penicillamine in dermatology: influence on enzymatic activities of human skin in vitro.

By in vitro assay, 6 important enzymatic activities of human skin homogenates were determined following an incubation with D-penicillamine in concentrations between 10(-4) and 10 mg/ml, i.e. 67 X 10(-5) and 67 mM/l. The following enzymatic activities were recorded: lactate dehydrogenase (LDH), glucose-6-phosphate dehydrogenase (G-6-PDH), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), alkaline phosphatase (AP), acid phosphatase (AcP), and "leucine aminopeptidase" (LAP). A dose-dependent activation by D-penicillamine occurred in the case of G-6-PDH- and AcP-activities, a dose-dependent inhibition by D-penicillamine was found with AP- and GAPDH-activities. LDH- and LAP-activities remained unchanged in the presence of D-penicillamine in concentrations up to 10 mg/ml (67 mM/l). From the data of pharmacokinetic studies in rats it may be concluded that concentrations of D-penicillamine which influence enzymatic activities may easily be reached in vivo, under the conditions of treating rheumatoid arthritis and Morbus Wilson. The biochemical actions of D-penicillamine are briefly discussed with secial regard to dermatological therapy and dermatological unwanted side-effects.