32 



Scientific Proceedings (26). 



17 (273) 



The effect of stimulation of the vagus nerves upon the develop- 

 ment of rigor mortis of the mammalian heart. 



By DON R. JOSEPH and S. J. MELTZER. 



\From the Department of Physiology and Pharmacology of the 

 Rockefeller Institute for Medical Research.] 



Stimulation of motor nerves hastens the onset of rigor mortis 

 in the corresponding skeletal muscles. Cutting the nerves retards 

 it, the retardation being due, it is believed, to the elimination of 

 subminimal nerve impulses. Would the retardation of the rigor 

 be still greater if inhibitory nerves could be stimulated ? This 

 question is not applicable to skeletal muscles, but it is a definite 

 problem with reference to the onset of rigor in the heart muscle. 

 Would a prolonged effective stimulation of the vagus nerves retard 

 the onset of cardiac rigor? There were reasons to expect that 

 the effect of such a stimulation would be indeed a retardation. 

 The action of the cardiac vagus is inhibitory and the reverse of the 

 action of a motor nerve ; we might then expect that the effect of its 

 stimulation upon cardiac rigor would also be the reverse of the effect 

 of stimulation of a motor nerve upon the skeletal muscles, that is, 

 retardation instead of hastening. Furthermore, increased muscular 

 activity hastens the onset of rigor ; it seemed reasonable to antici- 

 pate that the diminished activity, such as frequent standstill or 

 slowing of the heart, would retard the onset of its rigor. 



We have studied this question in 42 dogs, 16 cats and 10 rab- 

 bits. Both vagi were stimulated for half an hour before death and 

 frequently also after death. Death was caused uniformly by bleed- 

 ing and opening of the thorax. The outcome was a surprise ; the 

 obtained results were just the reverse of what was expected. But 

 the results were uniform and unmistakable. We shall state them 

 very briefly. They are as follows : 



In all animals in which the vagi were stimulated, left and right 

 ventricles stopped beating after death sooner than in the controls. 

 The interval between the time of death and the beginning of the 

 rigor in the left as well as in the right ventricle is in the experi- 

 mented animals shorter than in the controls. The time elapsing 



