Effect of exercise on plasma kallikrein and muscular phospholipase A2 activity in rats

Many experimental observations show that prolonged physical exercise produces an increase of muscular glucose uptake. Recent findings suggest that the kallikrein-kinin-prostaglandin system may be related to this phenomenon, but so far, no direct evidence of quantitative alteration in this system has been observed during exercise. We measured plasma kallikrein and muscular phospholipase A2 activity, respectively the first and the last steps of reactions leading to prostaglandin synthesis. We demonstrated, for the first time, that during exercise plasma kallikrein activity increases in rats. We also observed an increase of muscular phospholipase A2 activity after exercise and a positive correlation between these parameters. Our findings demonstrate, under physiological conditions of enhanced muscular glucose uptake, a concomitant significant increase of plasma kallikrein and muscular phospholipase A2 activity, supporting the hypothesis that activation of the kallikrein-kinin-prostaglandin system may play some part in the enhanced muscular glucose uptake during physical activity.