Brain protein synthesis rates are not sensitive to elevated GABA, taurine, or glycine.

The effects of elevated levels of GABA, glycine, or taurine on the rate of protein synthesis in plasma, brain, liver, and muscle of adult mice were measured in in vivo experiments after a flooding dose of labeled valine. Elevation of these amino acids caused hypothermia; keeping the animals in an incubator maintained physiological body temperature. The increase in GABA or glycine did not affect the rate of protein synthesis in these tissues to a significant degree. The increase in taurine levels caused inhibition of valine incorporation in plasma, liver, and muscle, while brain protein synthesis was unaffected. When glycine was increased in brain, the uptake of labeled free valine in the brain was greater.