Effect of Feeding and Fasting on Sugar Utilization of Eviscerated Rabbits

In an earlier paper by one of us 1 it was shown that the eviscerated rabbit utilizes glucose at a rate that is quite definite and fairly constant for a given animal. The rate varies, however, between different rabbits. The suggestion was made in that paper that this variation was due to the differences in the degree of fasting to which the different animals had been subjected prior to operation and that the effect of fasting is to reduce the utilization rate of the eviscerated animal. The work here reported was planned to investigate this relationship. The same technique was used as in the previous work. Essentially this consisted of measuring the rate at which glucose had to be administered to the eviscerated rabbit to maintain the blood sugar at a constant normal level.

Frequent blood sugar determinations served as a guide to the injection rate; if the blood sugar level rose the rate would be diminished, and vice versa. The determination was started 3 hours after completion of the operation and continued for 4 hours thereafter. Only those animals that sat up in normal posture and had normal righting reflexes after operation were used. The animals were also tested for kidney function by injecting phenol red after the operation. Any animals not secreting this dye were eliminated from the series. Ten rabbits were used in each of the two groups—one group fed to the time of operation, and the other fasted 4 to 6 days prior to operation. The glucose utilization rates are given in Table I. The rates are given for the period between the 3rd and the 7th hours after operation, In this way we could be sure that we were not getting any anesthetic effect.