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The Antagonistic Action of Carbon Dioxide and Adrenalin on 



the Heart. 



By S. W. Patterson, M.D., Beit Memorial Eesearch Fellow. 

 (Communicated by Prof. Starling, F.R.S. Received August 14, 19 14.) 



(From the Institute of Physiology, University College, London, and the Physiological 

 Institute of the University, Berlin.) 



Although a great volume of work on asphyxia has been published, it is only 

 comparatively recently that attempts have been made to dissociate the 

 influence of various factors in the production of the phenomena observed. 

 Kaya and Starling (1) were the first to differentiate the effects of lack of 

 oxygen and excess of carbon dioxide in the spinal animal ; and their work 

 was elaborated by Mathison (2, 3), in whose papers a full discussion of the 

 previous literature will be found. He found that during nitrogen adminis- 

 tration no increased output of the heart is seen in the early stages of 

 asphyxia, and attributed the increase in output noticed in ordinary asphyxia 

 to the presence of increased tension of CO2 in the blood, which Jerusalem 

 and Starling (4) had shown to increase the systolic output of the cat's heart. 

 He also observed an acceleration of the heart beat about the time of the 

 primary blood pressure rise in asphyxia, which occurred even after removal 

 of the upper part of the spinal cord. Since the work of v. Anrep (5) and 

 Itami (6), a third factor, variations in the secretory activity of the suprarenal 

 glands, must be taken into consideration ; and the present paper contains an 

 account of an investigation of the action of carbon dioxide and adrenalin on 

 the heart isolated from the nervous system. 



Methods. 



The experiments reported in this paper were carried out mainly on dogs, 

 a few on cats, the animals being anaesthetised by inhalation of chloroform 

 and ether mixture, in the case of dogs after a preliminary hypodermic 

 injection of morphine. 



The isolated heart-lung preparation was made as described by Knowlton 

 and Starling (7). The systemic blood was taken off by a cannula in the 

 brachiocephalic artery after ligation of the left subclavian artery and the 

 aorta beyond ; and was returned to the heart by a cannula tied in 

 the superior vena cava after ligation of the azygos vein. The mean blood 

 pressure was recorded by a mercury manometer connected to the side of 

 the innominate cannula, and the side pressure of the blood from the venous 

 return by a water manometer connected with a cannula tied in the inferior 

 vena cava close to its entrance into the right auricle. To the top of the water 



2 F 2 



