226 K. G. HOSKINS 



effects were obtained. The minimal dose used was 0.02 mg. Campbell 

 (1911) reported twelve perfusion experiments upon cats and rabbits. In 

 most cases he obtained slight diminution in the outflow. Baehr and Pick 

 (1913) obtained no distinct effect when Tyrode's solution containing 0.01 

 mg. of epinephrin per liter was perfused through guinea-pigs' lungs. 

 Fiihner (1913) noted constriction as the result of perfusing isolated dog's 

 lung with epinephrin solution. Tribe (1914) reported an extensive series 

 of perfusion experiments upon the lungs of cats, dogs, rabbits, guinea-pigs, 

 rats, and ferrets. She used defibrinated blood as the perfusing medium. 

 With dilute solutions (0.00002 mg.) dilatation was obtained, while with 

 larger doses (0.01 mg.) constriction resulted. Schafer and Lim (1919) 

 have reinvestigated the problem very carefully. Cats and rabbits were 

 used. The range of dilution of the epinephrin was from 1 :2,000 to 

 1 :62,000. In nearly every case constriction resulted. 



Thus most observers who have studied the problem have found that 

 epinephrin results in constriction of the pulmonary blood vessels. In a 

 few instances, however, dilatation has been reported. This has resulted 

 from the smaller doses and such as supposedly approach the physiological. 

 As nearly as data now available permit one to judge, the concentration of 

 epinephrin used by most of the observers was hundreds or thousands of 

 times as great as that in the normal blood-stream. The data are of corre- 

 spondingly slight physiological significance. 



The effects of epinephrin upon the pulmonary circulation of the living 

 animal have been studied by a number of observers. Cybulski (1897) is 

 quoted as having noted that intravenous injections of suprarenal extract 

 produced a slight rise of pulmonary pressure, which was ascribed to back 

 action from the systemic vessels. He worked on dogs under the influence 

 of curare. Velich(fr) (1898) obtained similar results, as did also Gerhardt 

 (1900). Mellin (1904) recorded the effects of epinephrin upon the pul- 

 monary and aortic blood-pressures simultaneously, using curarized rabbits 

 as experimental animals. He found that epinephrin in quantities sufficient 

 to cause a great rise of systemic blood-pressure had practically no effect 

 upon the pulmonary circulation. Plumier, as previously noted, obtained 

 marked increase in both pulmonary and systemic pressure, but he used 

 relatively enormous doses. Rise in pulmonary pressure under the same 

 conditions has also been noted by Pettijean (1908) and by Weber (1910). 

 Desbouis and Langlois (1912), having noted the reports of earlier investi- 

 gators that reversal in the systemic blood-pressure reactions to epinephrin 

 can be obtained by changing the dosage, investigated this point in relation 

 to the pulmonary circulation. Using an electrical method, they determined 

 the rate of blood flow through the lungs of the dog. With smaller doses, 

 0.025 or 0.05 mg., accelerated flow was noted. With larger doses, as 1 mg., 

 marked retardation of the flow was seen. Similar results had been re- 

 ported by Edmunds (1907). Anderes and Cloetta (1916) came to the 



