RELATION SUPRARENAL GLANDS TO CIRCULATION 225 



epinephrin were made into the rubber tubing near the aortic cannula. 

 Perfusion pressures of 50, 75, and 100 mm. of murcury were employed, 

 the temperature of the fluid being held constantly at 38 C. In the rabbit 

 doses of epinephrin varying from 0.025 to 0.25 mg. were used. In 

 the monkeys the dosage varied from 0.025 to 2 mg. In the rabbits the 

 reaction was always increased coronary outflow. In the monkeys the 

 results, on the other hand, were precisely the opposite, decreased flow. 

 This decrease was obtained under all conditions of high or low per- 

 fusion pressure, with beating or resting hearts, and with all effective 

 doses. 



The same criticism may be offered against these as against many other 

 experiments upon the pharmacology of epinephrin, namely, that concentra- 

 tions grossly out of proportion to those to which the tissues are exposed 

 under normal conditions were employed. So far as the writer is aware, 

 no experiments upon primates have been recorded in which the quantitative 

 factor received due consideration. Moreover, before the conclusion can 

 be definitely accepted that epinephrin causes coronary constriction it will 

 have to be demonstrated in the intact animal with conditions kept as 

 nearly physiologic throughout as possible. 



Effects of Epinephrin upon Pulmonary Circulation. The first direct 

 studies of the effects of epinephrin on the pulmonary circulation were 

 made in 1904 by Brodie and Dixon and by Plunder (a). The latter 

 experimented with dogs under morphin-chloroform anesthesia. Monom- 

 eters were connected with the carotid artery, the pulmonary artery, and 

 the right auricle. Epinephrin, in doses of 0.5 to 1.0 mg., was administered 

 intravenously. This resulted in an increase in both the pulmonary and in 

 the carotid blood-pressure, as well as the pressure in the auricle. That 

 the increased pulmonary pressure was not a "backing-up" effect was 

 shown by cutting the vagi. Under these conditions the augmented pressure 

 in the left auricle no longer appeared but increased pulmonary pressure 

 persisted. Plumier also noted the effects of epinephrin on the venous 

 outflow from the lung perfused with defibrinated blood. The addition of 

 epinephrin in rather large quantities (0.5 mg.) caused a marked decrease 

 in the outflow. 



Brodie and Dixon' s studies were very similar to those of Plumier, 

 except that they used relatively smaller doses. Isolated lungs of dogs, 

 cats, and rabbits were perfused with the animal's own defibrinated blood. 

 The addition of such quantities of epinephrin as 0.05 mg. produced either 

 no effect or an increased outflow. Wiggers(fc) (1909) reported similar ex- 

 periments upon the lungs of three dogs and one rabbit ; he perfused one 

 lobe at a time. The experiment was brief in each case to forestall the 

 effects of edema. As a menstruum, either Locke's solution or gelatin in 

 sodium chlorid solution to give a viscosity equal to that of the blood 

 was used. When the viscosity factor was thus controlled, only constrictor 



