Effect of Amytal upon Basal Metabolism in Guinea Pigs. 20

Abstract

Deuel, Chambers and Milhorat 1 have shown that there was only a very slight lowering of basal metabolism in dogs which had been injected with sodium amytal. A series of experiments was carried out to determine what effect doses of amytal sufficient to cause the animals to remain quiet would have upon the basal metabolism of normal guinea pigs, and upon guinea pigs which had been given various substances which would cause a rise in the basal metabolic rate. We used the isoamylethylbarbituric acid (Amytal—Lilly) which was prepared according to the directions given on the label of the bottle. 0.10 cc. of a saturated solution of the potassium salt of the amytal was injected subcutaneously into guinea pigs which had an average weight of about 400 gm., 5 or 10 minutes before placing the animals on the metabolism apparatus. The guinea pigs remained perfectly quiet throughout the 2-hour period in which they were on the apparatus. No shivering occurred. No ill effects from the use of the amytal and no increased tolerance for the drug were noted. The average basal metabolism of 76 normal guinea pigs without amytal was 3.59 calories per kilo per hour, while in 72 other guinea pigs which had been injected with amytal, the average basal metabolism was 3.52 calories per kilo per hour. Thus the average metabolism of this latter series was approximately 2% below the average of the series which had not received amytal. The maximum and minimum variations are approximately the same in both sets, being plus or minus 10%. Twenty-four guinea pigs were used to determine what effect amytal has upon basal metabolism if various substances are given which cause a rise in the basal metabolic rate.