Abstract: | Abstract— The intracellular concentrations of a number of amino acids were measured in a normal clone of rat glioma cells, and in several independently derived clones selected for gross deficiency of the enzyme hypoxanthine-guanine phosphoribosyltransferase (HGPRT). A significant, approx 2-fold increase in the concentration of free glycine was observed in both mutagenized and non-mutagenized HGPRT deficient clones. The increase in glycine was independent of the phase of cell growth. A similar increase did not occur in HGPRT deficient lymphoblasts. |