58 Society for Experimental Biology and Medicine. 



flow, but also a slight backward movement, such as can be ac- 

 counted for by the stretching of the venous valves. 



40 (183) 



On vaso-motor nerves in the pulmonary circuit. 



By RUSSELL BURTON- OPITZ. 



[Front the Physiological Laboratory of Columbia University, at the 

 College of Physicians and Surgeons .] 



To test the existence of vaso-motor nerves in the pulmonary 

 circuit, the following method was devised : The inlet tube of the 

 stromuhr, recently exhibited by the author before this society, 1 

 was connected with a receptacle containing Ringer's solution and 

 the outlet tube with a button cannula, to be inserted subsequently 

 into the pulmonary artery of dogs. The chest wall having been 

 resected, loose ligatures were placed around the nerves in the 

 vicinity of the ganglion stellatum and the pulmonary artery. A 

 cannula was inserted into the appendix of the left auricle. 



The procedure was as follows : Long forceps-clamps were 

 quickly placed upon the central portion of the pulmonary artery, 

 and transversely across the left auricle close to its junction with the 

 left ventricle. The button cannula having been inserted into the 

 pulmonary artery distally to the clamp, the blood-vessels of the 

 lungs were then supplied with circulating fluid from the receptacle 

 and drained by way of the cannula in the left auricle. Thus, all 

 influences of the heart which might have disturbed vaso-motor 

 reactions in the pulmonary circuit were excluded. 



A change in the flow directly attributable to vaso-motor in- 

 fluences, could not be obtained by stimulation of any of the afore- 

 said nerves. Stimulation of the vagus in the neck, as well as 

 centrally and distally to the ganglion stellatum, was ineffective. 



In view of these negative results, it seemed advisable to test 

 the influence of adrenalin upon the flow through the pulmonary 

 blood-vessels. A T-tube was inserted between the stromuhr and 

 the button cannula, through which solutions of different strengths 

 were injected. In spite of the fact that these solutions had pro- 



1 This volume, p. 24. 



