MODULATION OF PROCAINAMIDE TOXICITY BY SELENIUM-ENRICHED YEAST IN RATS

Free radical processes are proposed to play a crucial role in the deve lopment of procainamide adverse effects. Therefore, selenium, as a pot ent antioxidant, may modified procainamide toxicity. To test this hypo thesis plasma and Liver thiobarbituric acid-reacting substances (TBARS ), plasma antioxidant activity (AOA), erythrocyte and liver superoxide dismutase (SOD), catalase, as well as selenium-dependent glutathione peroxidase (Se-GPX) were determined in the following four groups of ra ts: selenium-treated (Se), procainamide-treated (P), procainamide and selenium-treated (P + Se), and control (C). Morphological studies of l eukocytes [tested for lupus erythematosus (LE) cells] and liver were a lso made. Atypical, i.e. enlarged and swollen, leukocytes resulting fr om procainamide and selenium treatment were observed. These changes we re found in four out of five rats in the Se group, eight out of ten in the P group, and in seven out of ten in the P + Se group. LE-like cel ls were observed in two rats in the P + Se group. A statistically sign ificant decrease in plasma and Liver TBARS by 20% and 36%, respectivel y, increased activity of SOD by 20%, catalase by 48% and Se-GPX by 15% in erythrocytes, and decreased activity of liver SOD by 17% and catal ase by 22% were found in the P + Se group as compared to the P group. These results indicated that selenium exerted antioxidant effects on t he procainamide-treated rats. However, selenium did not prevent the de velopment of disturbances in leukocyte morphology, on the contrary, it possibly promoted the conversion of leukocytes to LE cells.