PHAEMACOLOGY OF EPINEPHRINE 129 



isolated muscle. If a gastrocnemius muscle of a frog be stimu- 

 lated to fatigue, injection of epinephrine will give a good degree 

 of recovery. The irritability of frog's muscle stimulated 

 through its nerve is so much increased by epinephrine that 

 this drug may act as an antagonizer of curare. 252 



The claimed effects of epinephrine on skeletal muscle can 

 be explained by its action on the circulation, the rate of which 

 is increased, and its stimulation of the metabolic processes, by 

 increasing the oxygen consumption. The increased ability of 

 fatigued striated muscle to perform work in the presence of 

 epinephrine has also been ascribed to an acceleration in the 

 rate of formation of lactic acid. The phosphagen content of 

 the muscle is not at first affected but when most of it has been 

 decomposed, the accelerated formation of lactic acid furnishes 

 the energy necessary for the resynthesis of the phosphagen. 463 



BASAL METABOLISM 



Subcutaneous injection of epinephrine causes a rise of the 

 basal metabolic rate, as measured by the oxygen consumption, 

 which lasts for several hours. 544 In the rabbit, the injection of 

 one milligram subcutaneously causes an elevation of 50 per 

 cent or more in the basal metabolic rate which reaches its maxi- 

 mum in the third hour after injection. Injection of 0.1 mgm. 

 per kilo of body weight in the dog causes a rise from 350 cc. 

 to 490, after 20 minutes; 580, after an hour and a quarter; 

 480, after 3 hours. 639 



Since epinephrine does not affect the oxygen consumption of 

 an animal paralyzed with curare or of a perfused limb, Born- 

 stein 639 concluded that epinephrine exerts its metabolic effects 

 by central action. However, epinephrine raises the metabo- 

 lism of a rabbit after section of the spinal cord. It does not 

 raise the metabolism of an eviscerated animal. Epinephrine 

 injections stimulate the metabolism of hibernating hedgehogs 

 to such an extent as to raise their body temperature and 

 rouse them from their winter sleep. 639 



Epinephrine still causes an increase in the oxygen consump- 



