Glutamine metabolism by animal cells growing in a synthetic medium

1. 1. During growth on synthetic medium MD 705 1 mouse L cells consume uniformly labeled 14C-glutamine. The cells convert this amino acid to carbon dioxide, cell substances and soluble extracellular products. 2. 2. In 3 days carbon dioxide accounts for approximately 15 per cent of the administered glutamine. This amount is not sufficient to be considered as a principal source of energy for the cells. 3. 3. The only amino acids of the medium that are formed from the carbon structure of glutamine are glutamic acid and proline. 4. 4. The carbon of glutamine is incorporated in small but significant amounts into protein, lipid, DNA, and RNA of the cell. 5. 5. The incorporation of glutamine into protein is constant and unaffected by dilution with glutamic acid.