Selective uptake of [ 3H]glutamine and [ 3H]glutamate into neurons and satellite cells of dorsal root ganglia in vitro

Abstract

The uptake of [ 3H]glutamate and [ 3H]glutamine into rat dorsal root ganglia has been examined by autoradiography and thin-layer chromatography. [ 3H]glutamate was selectively accumulated by satellite glial cells and after 10 min, 53% of this had been converted to [ 3H]glutamine. [ 3H]glutamine, on the other hand, entered neuronal perikarya and 40% was converted to [ 3H]glutamate. It is suggested that these selective uptake processes provide supporting evidence for the existence of a neuronal-glial glutamine cycle in dorsal root ganglia. Small dark (B) cells accumulated 6 times as much [ 3H]glutamine as did large light (A) cells. The reasons for this marked difference in the metabolism of the two main types of dorsal root ganglion neurone are discussed.