[CAS NO. 56-85-9]  L-Glutamine

L-Glutamine (0.2 and 2 mM) but not D-Gln inhibits the generation of L-Arg by both Arg-depleted and nondepleted endothelial cells. L-Glutamine also inhibits the conversion of L-[14C]Cit to L-[14C]Arg by Arg-depleted endothelial cells. L-Glutamine interferes with the conversion of L-Cit to L-Arg probably by acting on argininosuccinate synthetase rather than argininosuccinate lyase. L-Glutamine also inhibits the generation of L-Arg by the monocyte-macrophage cell line J774 but has no effect on the conversion of L-Cit to L-Arg by these cells. L-Glutamine metabolism stimulates Na+-H+exchange of acid-loaded porcine enterocytes by a mechanism not requiring activation of PKC. L-Glutamine (0.2 mM and 2 mM) but not D-glutamine (2 mM), L-glutamic acid (2 mM) or ammonium chloride (1 mM) also inhibits the generation of L-arginine in endothelial cells. L-glutamine promotes chromatin condensation and formation of crescent-like structures in the nucleus of murine primary microglia as well as of the microglial cell-line BV-2.