.244 



FKAKK A. HARTMAE" 



creased depth being in proportion to the dose within certain limits. The 

 augmentation* might be as much as 35 per cent (Fig. 3). Doses of 0.3 

 c.c. or more of a 1 : 1,000 solution produce in a cat the opposite effect, viz., 

 a reduction in the amplitude of the breathing. Hfere the decrease within 

 certain limits is in direct proportion to the dose. These effects occur 

 whether the blood pressure be high or low and also regardless of whether 

 the vagus nerves are cut or not. When the breathing was irregular in 

 some animals epinephrin (small closes) made it regular. 



These authors were inclined to interpret the effect as due to a stimu- 

 lation of the nervous center for they were unable to* obtain any increase in 

 the contraction of isolated strips of diaphragm when stimulated electrically 



in the presencenpf epine- 

 phrin in a bath. More- 

 over, it has been shown 

 by perfusion of the 

 medulla (Brown) that 

 epinephrin acts directly 

 on the respiratory cen- 

 ter, small doses causing 

 increase in depth and 

 rate of respiration while 

 large doses dimmish the 

 depth and rate or may 

 even stop it. 



We have found this 

 respiratory effect to oc- 

 cur in man after the 

 injection of epineph- 

 rin. The intravenous 

 administration of 1.0 



c.c., 1 :50,000 dilution in a conscious subject caused an increase in the 

 respiratory rate from 24 per minute before, to 42 per minute after, while 

 amplitude was also increased. These changes lasted for 90 seconds. The 

 effect was not the result of suggestion because injections of distilled water 

 were given at times instead of epinephrin, the subject being kept in ignor- 

 ance of the kind of injection by use of these controls. However, this 

 subject was unusually sensitive because three others receiving similar 

 doses of epinephrin showed no changes in respiration except in one in- 

 stance in which there was a small increase in amplitude. 



Influence of Epinephrin upon Kidney Activity. That epinephrin 

 may exercise an important influence upon kidney activity is indicated by 

 the work of Cow and others. Cow demonstrated in the cat that there 

 is direct vascular connection between the suprarenal and the kidney. This 

 consists of a fine rete of vessels embedded in the perirenal fat and join- 



Fig. 3. Cat. Blood-pressure albove, record of 

 diaphragm contraction below. Augmentation of con- 

 traction by a depressor dose of epinephrin (0.35 c.c.. 

 1:50,000). (After Nice, Rock and Courtright, Am. J. 

 Physiol.) 



