PHARMACOLOGY OF EPINEPHRINE 131 



of the cervical cord and the hedgehog after removal of the 

 heat regulating center. 639 



CARBOHYDRATE METABOLISM 



Blum, 64 in 1901, first showed that an injection of epinephrine 

 causes glycosuria. He suggested that the glycosuria observed 

 by Claude Bernard after piqure of the floor of the fourth ven- 

 tricle was due to liberation of epinephrine. The glycosuria is 

 the result of hyperglycemia which in turn is brought about, in 

 part at least, by glycogenolysis in the liver. After large doses 

 of epinephrine, the liver may be depleted of its glycogen store. 

 This glycogenolysis is not prevented by severing the nerves to 

 the liver. The subcutaneous injection of 0.2 mgm. of epi- 

 nephrine into a rabbit causes an hyperglycemia of several hours 

 duration. Injected intravenously, on the other hand, the 

 effect is very short due to the rapid destruction of the epi- 

 nephrine. 128 



Even in doses which do not elicit a rise in blood pressure, 

 epinephrine still gives rise to hyperglycemia. Thus the con- 

 tinuous intravenous infusion of 0.0001 mgm. per kilo per min- 

 ute to a rabbit causes hyperglycemia, but is without effect on 

 the blood pressure. The effect of epinephrine on the blood 

 sugar varies in different animals, being greater, for example, in 

 rabbits than in cats, dogs, rats, or men. The hyperglycemia 

 which follows the injection of epinephrine no longer occurs, 

 as Mann and Magath 425 have shown, after removal of the liver. 

 However, the hyperglycemia may still be elicited in animals 

 in which the glycogen store of the liver has been reduced to a 

 minimum by prolonged fasting or by the injection of strych- 

 nine. In such animals obviously the liver can not be the 

 source of the glucose which appears in the blood stream. In 

 such fasting animals, indeed, not only does hyperglycemia 

 occur but there is also a concurrent storage of glycogen in the 

 liver. Further evidence against the view that the effect of 

 epinephrine upon the carbohydrate metabolism is due solely to 



