VOL. 4 (1950) BIOCHIMICA ET BIOPHYSICA ACTA II; 



NERVE CONDUCTION 



WITHOUT INCREASED OXYGEN CONSUMPTION; THE ACTION OF 



AZIDE AND FLUOROACETATE* 



by 



R. W. GERARD and R. W. DOTY 



Department of Physiology, University of Chicago (U.S.A.) 



The precise correlation of an extra oxygen consumption of active nerve with an 

 extra heat production was estabhshed nearly a quarter of a century ago by one of us in 

 Prof. Meyerhof's laboratory. It is an especial pleasure to report the present extension 

 of such studies, in his honour. Nor can we refrain from an expression of admiration for 

 his continued vigour of thought and research despite a weight of personal disaster that 

 would have crushed most men. 



That the extra energy release of nerve activity is essential to conduction and 

 recovery was taken for granted since its discovery. With energy sources blocked by 

 oxygen lack or lAA poisoning, conduction failed. With tetanization at a rate to limit 

 full development of the delayed heat and oxygen consumption, conduction was de- 

 pressed. Restoration of full metabolism restored full conduction in all cases. The actual 

 fuel burned proved not identical for rest and activity. True, both resting and active 

 metabolism seemed to focus on the production of energy-rich phosphate bonds, especi- 

 ally as creatine phosphate. And true, also, that the procedures that blocked conduction 

 affected resting as well as active respiration. Nonetheless, there seemed no reason to 

 question the essential contribution of the active respiration to actual conduction. A 

 tentative report by Schmitt, of a fall in oxj^gen consumption on stimulation of yohim- 

 binized nerve, was given little weight ; and Lorente de No's finding, that excitation 

 could be restored in a nerve blocked by anoxia, with the aid of a repolarizing current, 

 did not really question the necessity of the metabolism as a normal source of membrane 

 polarization. 



Yet it was early shown by Feng and in this laboratory that lactate, indifferent to 

 nerve conduction and metabolism under normal conditions, could restore resting oxygen 

 consumption and active conduction after lAA poisoning — suggesting some interchange- 

 ability of resting and active metabolic energy. Further, 90 to 97% of the energy of 

 activity is liberated after an impulse has traveled and the nerve again reset for action. 

 Moreover, a factor of safety of live for the resting metabolism could be estimated. 

 Activity might, then, be supported under emergency conditions by a portion of the 

 resting metabolism. Sodium azide, found by Stannard to eHminate the contraction 

 respiration of muscle, was tested on nerve in Bronx's laboratory and here and found 

 indeed able to abolish the extra oxygen consumption of active nerve while leaving 

 conduction intact and resting respiration largely so. We found, further, that methyl 



This work was performed under contract with the Office of Naval Research. 



