It is reported´ that penicillamine in the presence of Cu" inhibits function of immune cells and this inhibitory effect may be ascribed to the production of´ H2O2, whereas effects of other metal ions are not detected. In this study, in the presence or absence of Cu" and Fe", the production of oxygen radicals during oxidation of penicillamine was investigated. The effect of Cu" penicillamine complex was also compared with that of Cu" plus other thiol compounds.
Oxidation of penicillamine was stimulated by Cu", Fe" and H202 and stimulatory effect of Cu" was apparently greater than that of Fe" or H2O2 alone. Oxidation of penicillamine stimulated by either Cu" or Fe" was effectively inhibited by SOD and catalase. Oz- and H2O2 was produced during oxidation of penicillamine in the presence of Cu" and Fe". Reduction of .iNBT by either penicillamine plus Cu" or penicillamine plus Fe" was increased up to the proportion of concentration ofIpenicillamine to metal ion, 50:1, but fell off this proportion, reduction was decreased and when the proportion of penicillamine to metal ion was 10:1, reduc tion rate was significantly decreased. Reduc t tion of NBT `by penicillamine plus Cu++was apparently greater than that by penicillamiru t´ a, plus Fe++, more 3 times. The production of w O2- in the presence of Cu++ was significant ly enhanced by addition of penicillamine in a dose dependent fashion. Hydroxylation of sodium salicylate was markedly stimulated ;: by penicillamine plus Cu". Hydroxylation ´ of salicylate by penicillamine was not affected by H2O2. Hydroxylation of salicylate by Cu+ was markedly stimulated by cysteine, whereas it was inhibited by GSH and MPG These results suggest that oxidation of penicillamine appears to be stimulated by the direct interaction of penicillamine with metal ions and by free radicals produced from oxidation. Penicillamine-Cu++´ complex` may act
as an efficient promotor in the production, >-of oxygen radicals under certain concentration proportion of complex. In addition, pro oxidant effect of thiol compounds may´bc dependent on the ability of complex formation of thiol for metal ions.
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