94 



PHYSIOLOGY OF INDUCED HYPOTHERMIA 



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• -HIBERNATING HAMSTERS 



NORMAL HUMAN • 



( OAVIES ET AL 1925) 



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Fig. 9. — Effect of various concentrations of inspired CO^ in a series of four hamsters com- 

 pared to the response of man. Data on man from H. W. Davies, G. R. Brow, and C. A. L. 

 Binger, J. Exp. Med. 41:37, 1925. 



tially different from that of active animals,""' "'' it is apparent that this lowered O2 

 tension gradient is adequate to supply the metabolic needs of the animal in hiberna- 

 tion. A low pH or a high pCOo would tend to correct the situation by shifting the 

 dissociation curve to the right, and McBirnie, ct o/./^ suggest that this actually 

 occurs in hibernation. Their evidence, however, is based only on observed high total 

 CO2 with no reported pCOa or pH. 



Blood sugar. It has been reported for many species of hibernators that the blood 

 sugar is low during the period of hibernation, but the degree of hypoglycemia ap- 

 parently varies from species to species. Suomalainen'"-* has reported a drop from 

 152-110 mg.% in the normal awake hedgehog to 85-49 mg.% in the hibernating 

 animal. McBirnie, et al.,^^ have reported an average decline from 121 mg.% in the 

 normal woodchuck to 66.8 mg.% in the hibernator, but Endres''' found no decline in 

 the hibernating marmot. On the other hand, Stuckey and Coco^°° and R. A. T.yman^"^ 

 found a much smaller decline in hibernating thirteen-lined ground squirrels. 

 Musacchia and Wilber*^' found virtually no difference in the blood sugar content of 

 hibernating and awake arctic ground s(|uirrels, but showed that fasting animals 



