SummaryThe metabolism of glycine in mice has been studied after a single injection of glycine-2-C14 by following the specific activity of the uncombined glycine in plasma, liver and skeletal muscle, as well as the specific activity of the respiratory CO2. The size of the dynamic pool of glycine was found to be 30 mg per 100 g of which 10 mg per 100 g was uncombined glycine; the turnover time of the glycine pool was 1.5 hours and the rate of turnover 20 mg per 100 g per hour. The amount of glycine oxidized to yield CO2 in the breath was found to be approximately 10 times the amount of glycine ingested in the food.