PHYSIOLOGY OF EPINEPHRINE 103 



after adrenalectomy mydriasis of the pupil (after a previous 

 excision of the superior cervical ganglion) is still elicited by 

 nicotine injections. It has been suggested that the hyper- 

 glycemia which accompanies tobacco smoking is due to the 

 liberation of epinephrine. Other pharmacologically related 

 compounds behave similarly to nicotine, e.g., the tetramethyl- 

 ammonium salts, neurin, hordenin methyliodide, hydrastinin, 

 and 0-dimethyl telluronium salts. Cystisine, coniine, arec- 

 oline, spartein, gelsemin and lobelin also cause a discharge of 

 epinephrine. Choline and acetylcholine do not manifest an 

 appreciable effect on epinephrine secretion. 639 



Sympathetic and 'parasympathetic stimulants. Tetrahydro- 

 /3-napthylamine, which is a powerful stimulant of the sympa- 

 thetic nervous system, also stimulates the centers controlling 

 epinephrine secretion. The hyperglycemia following the injec- 

 tion of this drug is probably due to the liberation of epinephrine 

 for it does not occur in adrenalectomized animals or after 

 cutting the splanchnic nerves. The hyperpyexia following the 

 injection of tetrahydro-j3-napthylamine occurs in adrenalec- 

 tomized animals, and is thus not due to the liberation of 

 epinephrine. 75 - 602 



Although a sympathetic stimulant, epinephrine itself appar- 

 ently does not stimulate the medulla for its administration does 

 not increase the rate of discharge of epinephrine from the 

 adrenals. 603 - 635 



Of the parasympathetic stimulants, physostigmin is an active 

 stimulant of epinephrine secretion. Pilocarpin has only a 

 feeble action. 171 Atropin does not inhibit epinephrine secretion 

 but appears to stimulate it. Quinine causes an increased 

 secretion. 



Curare in doses sufficient to paralyze the skeletal muscles of 

 the cat markedly depresses the output of epinephrine from the 

 adrenals. 



Morphine. Morphine may reduce the epinephrine content 

 of the cat's adrenals to one-seventh of their normal value. 590 



