EFFECT OF EXCESSIVE AMOUNTS OF VITAMIN B ON THE BASAL METABOLISM OF RATS OF DIFFERENT AGES

Abstract

White rats (5 litters) on a constant ration plus yeast vitamin, were individually subjected to basal metabolism determinations by the Haldane method. The respiratory quotient was determined from O2 consumption and CO2 production during 4-6 hours. The rate of heat production was determined for 20-25 minutes while the rat was at rest. The respiratory quotient of the fasted rats was nearly constant at 0.75. For rats 90-190 days old the basal metabolism when referred to body surface (but not when referred to weight) was greater and more variable for [male] than for [female] ; the average found in cal. per sq. m. for [male] was 600 [plus or minus] 11 and for [female] 571[plus or minus]7. For both sexes the variability was higher on the weight basis than on the surface basis. Within the above age limits age did not affect basal heat production, but that of younger rats was higher. The ingestion of excessive amounts of vitamin B up to 10 times the estimated requirement did not modify basal heat production.