Glycine cleavage system in astrocytes.

The localization of the glycine cleavage system was examined in the rat brain by immunohistochemistry using an antibody to P-protein (a constituent of the system). In all sites studied, the enzyme was confined to the astrocytes. The intensity of astrocyte staining varied in different brain regions, with the strongest staining being noted in the hippocampus, the cerebellar cortex, the Bergmann glia in the cerebellum and the Muller cells in the retina. The weakest staining was seen in the brainstem and spinal cord. P-protein was found to be located in the mitochondria by an ultrastructual study.