A TECHNIQUE FOR MEASURING BRAIN PROTEIN SYNTHESIS

Abstract
Abstract— Mice were infused intravenously for varying periods of time with L‐[U‐14C]‐ tyrosine. The specific activity of free tyrosine in the blood and the brain, and of protein‐bound tyrosine in the brain, was measured and the mean rate of protein synthesis calculated. The half‐life of mixed brain proteins was found to be close to 4 days with infusions lasting 0.5–2 h.The origin of the intracellular tyrosine pool was investigated and it was shown that 60 per cent of this was derived directly from the plasma tyrosine and 40 per cent from protein breakdown within the tissue.