EFFECT OF WORK UPON TOLERANCE OF THE NORMAL RAT FOR INTRAVENOUSLY ADMINISTERED GLUCOSE

Abstract

Male rats weighing 200 g. were fasted for 24 hrs., anesthetized with phenobarbital sodium, then given continuous intraven. injns. of solns. containing glucose and heparin for 72 hrs. In one series of animals the study was made under resting conditions, in the 2d both hind legs were stimulated to contract 5 times per sec. The highest glucose load tolerated by the inactive rats was 100 mg/100 g. body wt./hr. In the stimulated rats glucose loads of 100, 125 and 150 mg./lOO g./hr. were tolerated without causing hyperglycemia during any phase of the expt.; loads of 200, 225, 275, and 300 mg./lOO g./hr. caused an initial hyperglycemia, but during the last 24 hrs. the blood glucose decreased to nearly normal value. The upper limit of glucose tolerance for the working rat was not reached on these expts.