Regulation of erythrocyte antioxidant enzyme activities in athletes duringcompetition and short-term recovery

We have determined "in vivo" the influence of strenuous prolonged exercise and short-term recovery on erythrocyte antioxidant enzyme activities. We ha ve also determined the "in vitro" effects of the xanthine/xanthine-oxidase- generating superoxide anion system on catalase activity in haemolysed eryth rocytes. Haematological parameters and erythrocyte superoxide dismutase (SO D), glutathione peroxidases and catalase activities were measured in nine h ealthy duathlon athletes under basal conditions, at the finish of a competi tion and after 1 h of recovery. We also measured catalase activity in haemo lysed erythrocytes - obtained from four overnight-fasted well-trained sport smen before and after an 80% submaximal exercise test on a cycle-ergometer - prior to and after incubation for 3 min with the superoxide-anion-generat ing system. Duathlon competition and/or short-term recovery produced a slig ht haemolysis and increased the activity of catalase and peroxidases but no t SOD enzymes. The observed changes in catalase activity were mimicked "in vitro" by the superoxide-anion-generating system.