Compartmentation of amino acid metabolism in the rat dorsal root ganglion; a metabolic and autoradiographic study.

The incorporation of radioactivity into glutamate, glutamine, GABA and other amino acids was followed after incubation of desheathed rat dorsal root ganglia in media containing [14C]glucose or [14C]acetate. The results indicated that [14C]glucose was incorporated into a large pool of glutamate, but that this glutamate pool did not synthesize glutamine or GABA to any great extent. [14C]Acetate, on the other hand, was incorporated into a small glutamate pool which was readily converted to glutamine, and which synthesized GABA to a greater extent than the large pool. Light microscopic autoradiography of ganglia incubated with [14C]glucose or [14C]acetate confirmed that the small pool labelled by acetate was probably associated with satellite glial cells, while the large pool was located within the ganglion neurons. The results are discussed within the context of previous work on compartmentation of glutamate metabolism in the central nervous system.