Maximal Aerobic Metabolism of Mice During Swimming 1

Abstract

Summary

Using swimming stress to evaluate the effects of experimental conditions, the maximal oxygen consumption seems to be a preferable measurement to swim time to exhaustion. Mice swimming to exhaustion with 7% weight load in 36° water exhibited similar Vo_2max values for their first and second exposures. However, swim time more than doubled for the second exposure. Almost no correlation existed between Vo_2max and swim time. This suggests that swim time is dependent on several factors, both physiological and psychological, other than aerobic power.

Mean maximal Vo₂ for mice with 0 and 5% loads was about 140 ml/kg/min. This response was achieved well within the 5-min duration of the test and was consistent for three trials. At 7% load, Vo_2max was lower as difficulty was encountered remaining at the surface. This Vo₂ test appears suited for experimental designs which require groups of mice to be tested several times. The duration of the test is relatively short, and no previous training is necessary. In addition, because of the high relative Vo₂ of mice, they seem to be well suited for experiments which may alter the ability to pick up, deliver and consume oxygen.

The authors express their appreciation to Mr. Joseph F. Pitt for his assistance.