EFFECT OF MUSCLE WORK UPON TOLERANCE OF EVISCERATED RAT FOR GLUCOSE

Abstract

The effect of work upon the tolerance of the eviscerated rat for intraven. admd. glucose was studied during a period of 2 hrs. In expt. 1, the gastrocnemius muscle of one leg was stimulated to lift 100 g. at the rate of 5 times per sec. The avg. glucose load tolerated by the non-working rat without insulin was approx. 16 mg. per 100 g. of rat per hr. (16/100/hr.); with insulin the value was 72/100/hr. Under similar conditions the stimulation of one leg in rats without insulin increased the tolerance for glucose to approx. 48/100/hr.; with insulin the approx. value was approx. 110/100/hr. In expt. 2, the stimulus passed from one back foot to the contralateral back foot, thereby activating the entire musculature of both hind legs. The avg. value for glucose tolerance without insulin was approx. 160/100/hr.; with insulin the approx. value was 220/100/hr. Work performance was roughly proportional to the glucose load in those animals which did not receive insulin. The admn. of insulin suppressed work performance at the lower glucose loads. In no instance did admn. of insulin enhance the ability of the eviscerated rat to work.