[The effect of benzylpenicillin on the activity of antioxidative enzymes in the erythrocytes and on methemoglobin formation in children].

Activity of erythrocyte antioxidative enzymes and the content of methemoglobin were studied in 36 healthy children under preventive treatment with benzylpenicillin and in 65 healthy children of the control group. It was shown that there was relationship between the changes in the activity of superoxidodismutase and catalase and the antibiotic dose and duration of the use. After benzylpenicillin intramuscular administration for 3-4 days (the total dose of 80,000-3000000 units) the catalase activity decreased to 65.6 per cent while the activity of superoxidodismutase did not change. When the antibiotic was used for 1-2.5 weeks (the total dose of 3000000-6000,000 units) the activity of catalase and superoxidodismutase decreased to 53.6 and 82 per cent respectively. Beginning from the 3rd week of the antibiotic use the catalase activity increased to 71.6 per cent while the superoxidodismutase activity did not change and remained at the level of 84.9 per cent. The content of methemoglobin in the children treated with benzylpenicillin was about 3 times higher than that in the controls. The correlation between the activity of the antioxidative enzymes and the content of erythrocyte methemoglobin was inverse: the lower was the enzyme activity, the higher was the content of methemoglobin and vice versa. It was concluded that benzylpenicillin impaired definite balance between single electron reduction of oxygen and antioxidative protection resulting in the antibiotic adverse action i. e. increased methemoglobin formation. The effects of benzylpenicillin should be considered when it is used in combination with oxidants in treatment of children.