INFLUENCE OF MUSCULAR EXERTION UPON METABOLISM. 22% 
maintained during fasting until the very: last stages of inanition. 
When it finally disappears there is a rapid fall in the body temper- 
ature and death speedily follows. 
4, Both the production of dextrose by the liver and its con- 
sumption in the tissues appear to be augmented by muscular exer- 
tion. 
The latter fact is shown by the well-known experiments of 
Chauveau & Kaufmann * upon the masseter muscle of the horse. 
Comparing the amount of blood passing through the muscle and 
the decrease in its percentage of dextrose in rest and in work they 
found that the consumption of dextrose in the two cases was in the 
proportion of 1:3.372. Subsequent experiments ¢ upon the Leva- 
tor labix superioris of the horse, the results of which as to the gaseous 
exchange have already been cited (p. 188), gave the following 
figures for the dextrose abstracted from the blood per kilogram of 
muscle in one minute: 
Rest, Grms. Work, Grms. Work + Rest. 
Experiment 2.................. 0.00598 (?)| 0.07026 (?) 11.75 
Ke Suede a inaea na ae sien 0.06358 _ 0.22303 (38.51 
oe Aa ee sk ih deena tele 0.03976 (?) 0.12852 3.23 
Average 0.00.6. eee cee eens ..| 0.03644" | 0.14027 3.85 
The authors also call attention to the fact that in these two 
series of experiments the arterial blood supplied to the active muscle 
contained a higher percentage of dextrose than that supplying the 
same muscle in a state of repose, notwithstanding the consumption 
of this substance by the muscle, and conclude that muscular activ- 
ity stimulates the production of dextrose by the liver. The observa- 
tion of Kiilz,t that prolonged muscular exertion may cause the dis- 
appearance of glycogen from the liver, may perhaps be interpreted 
as sustaining this conclusion. 
* Comptes rend., 108, 974, 1057, 1153. 
} Ibid., 104, 1126, 1352, 1409. 
{ Arch. ges. Physiol., 24, 41. 
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