Relation between natriuresis and urinary excretion of hydrogen peroxide

Changes in the urinary hydrogen peroxide by exercise or salt load were studied in six healthy male volunteers. Exercise was performed by bicycle ergometer for 30 min at the intensity of 80% of the maximum heart rate predicted by age. Urinary excretion rate of hydrogen peroxide showed a tendency to increase in the salt load experiment, and to decrease by exercise. Correlation coefficient between urinary excretion rate of sodium and hydrogen peroxide one hour after the load was 0.797 (0.1 > p > 0.05) in the exercise experiment, 0.892 (p < 0.05) in the salt load experiment and 0.877 (p < 0.001) in both experiments. Correlation coefficient between area under the curve for sodium excretion and hydrogen peroxide excretion was also as high as 0.822 (p < 0.05) in the exercise experiment, 0.909 (p < 0.05) in the salt load experiment and 0.853 (p < 0.001) in both experiments. These results may suggest that urinary excretion rate of hydrogen peroxide is closely related to metabolism of electrolytes and fluid in the renal tubules.