Changes in glycine content in mouse brain during hypoxic preconditioning.

Glycine content of the whole brain and subregions was measured by high pressure liquid chromatography (HPLC) in mice during their repetitive exposures to hypoxia. The contents of glycine in whole brain, diencephalon, and hippocampus and brain stem was significantly increased as the animals tolerance to hypoxia was increased. The results suggest that glycine, as an inhibitory neurotransmitter in the brain, may positively contribute to the development of hypoxic preconditioning.