A comparative analysis of compartmentation of metabolism in the dorsal root ganglion and ventral spinal cord gray using [U-14C]glucose, [2-14C]glucose, [6-14C]glucose, [3,4-14C]glucose, NaH14CO3, and [2-14C]pyruvate.

A detailed temporal comparison of glucose metabolism, in the production of glutamate and glutamine as well as aspartate and alamine, was conducted in order to further define the uniqueness of the dorsal root ganglion compared to the ventral spinal cord gray. Experiments with injected labeled NaHCO3 and pyruvate were used in an attempt to clarify certain aspects of the above results with different [14C]glucose precursors. The glutamine/glutamate relative specific activity ratio (RSA) was consistently lower in the ganglion than in the ventral spinal cord gray, as was also true for glutamate specific activity from the same amount of injected [14C]glucose. The ganglion is characterized by a high level of alanine production from glucose and pyruvate. The NaH14CO3 experiments suggest that CO2 fixation from [3,4-14C]-glucose in the dorsal rool ganglion resul .ts in a higher glutamine/glutamate RSA when compared to results using either [6-14C] or [2-14C]glucose.