Glucose Requirement of Hepatectomized Rabbits and Its Relation to Lactic Acid Production

Abstract

We have previously reported 1 on the minimal glucose requirements of the hepatectomized rabbit during the first 6 to 8 hours after operation. During that period, a constant intravenous injection at the rate of 125 mg. of glucose per kilo per hour will maintain a normal blood sugar level. The oxygen consumption of these animals indicated that they would have required 500 mg. glucose per kilo per hour if their energy requirements had been entirely supplied by glucose. The difference between these two figures represents mainly the amount of fat oxidized, expressed as its glucose equivalent. The respiration quotients of approximately 0.77, in these animals, bears out this assumption.

The blood sugar level can be maintained in liverless animals for periods up to 15 hours after operation by the injection of glucose at the rate above mentioned. Eventually, however, the blood sugar begins to decrease and the amount of glucose must be increased to bring it back to normal. Thereafter added increases must be made at least every hour to maintain the blood sugar level. Finally, a rate of about 500 mg. glucose per kilo per hour is arrived at, which is the maximum amount ever required and one on which the normal sugar level can be maintained until the animals die.

It is at the time when the first increase in the quantity of glucose is required that the symptoms of the so-called second stage after hepatectomy develop. At its beginning there is restlessness and irascibility, then blindness and ataxia, followed by extreme weakness, and coma. We noticed that the lactic acid content of the blood became higher as the second stage progressed and it seemed pertinent to ascertain whether the increase in the glucose requirement of the liverless animal is due to an incomplete utilization of glucose by the organism, with the production of lactic acid.