GLUCOSE AND OXYGEN UTILIZATION IN SYMPATHETIC GANGLIA 



TABLE IV 



Calculated formation of ^P (mM/dry g. hr.) in rat 

 ganglia at rest, assuming P/O = 3 and P/G = 2 



* Median of 8 experiments, 2 hours after withdrawal of glucose. 



sence of oxygen (Table IV). These figures further suggest that the amount of 

 non-oxidative energy yielded from glucose metabolism is normally a relatively 

 small portion of the total energy supply. 



Metabolism During Activity 



Recently we have succeeded in measuring glucose and lactate exchanges 

 during various states of activity in rat ganglia. This was made possible by the 

 electrode assembly shown in Fig. 6. It was constructed of fine platinum 

 wires imbedded in glass with projecting loops through which the nerves could 

 be drawn. The ganglion and electrodes were dipped in the bathing solution 

 once a minute. By coating the lower end of this structure with Desicote, good 

 drainage was obtained when the solution was lowered. Thus stimulation was 

 not short-circuited by fluid and action potentials could be recorded, usually 

 free of stimulus artifact. There was relatively little decline in height of response 

 during prolonged stimulation at frequencies up to 10 per second. 



Using these methods, consistent and sizable increases in rate of glucose 

 uptake were found during repetitive stimulation. The examples in Fig. 7 

 were caused by stimulation at 15 per second. 



Large increments in rate of glucose uptake during stimulation were reported 

 for excised spinal cords of frogs by Hirschberg and Winterstein (1917) and 

 later for frog peripheral nerves by the same authors (1919). By contrast Holmes, 

 Gerard, and Solomon (1930) were unable to find acceleration of carbohydrate 

 disappearance during activity in nerve trunks from frogs or rabbits. In these 

 latter experiments no exogenous glucose was supplied. Further results on frog 

 nerve which might at first glance also seem to disagree with ours have been 

 reported recently by Mullins (1953). Using tracer techniques, Mullins found no 

 increase in yield of radioactive COo from tagged glucose during stimulation. 

 But it turns out that our observations are reconcilable with those of Mullins, 



