PROTECTION BY L-ASCORBIC-ACID AGAINST PHOTOTOXICITY IN TIN-PROTOPORPHYRIN-TREATED SUCKLING RATS

The protective effect of free radical scavengers against phototoxicity was investigated with tin-protoporphyrin (SnPP)-treated suckling rats . Six kinds of scavengers (L-ascorbic acid, reduced glutathione, alpha -tocopherol, retinol, uric acid and cystine) were intraperitoneally in jected to rats treated with Snpp plus photoirradiation. Among them, L- ascorbic acid was found to be most effective in protecting SnPP-treate d rats against phototoxicity. The survival period was markedly prolong ed, and the frequency of abnormal behaviors was reduced with the treat ment. Lipid peroxidation in vitro with the brain membrane fraction was also suppressed. The other five substances gave only a little antioxi dant effect both in vivo and in vitro. The present study shows that L- ascorbic acid may be a promising chemical to prevent the phototoxicity of SnPP.