Deuterium‐Labelling of sn‐Glycerol 3‐Phosphate during Metabolism of [1‐2H2]Ethanol in Rats

The incorporation of deuterium into different positions of sn‐glycerol 3‐phosphate in liver and into glucose in plasma of rats given [1‐2H2] ethanol has been determined. The labelling of sn‐glycerol 3‐phosphate reached a steady state after about 1 min. The deuterium excess was about 5 atoms% at C‐1, 15 atoms% at C‐2, and 5 atoms% at C‐3. Plasma glucose contained less than 2 atoms% deuterium. Administration of glucose or fructose did not influence the labelling of sn‐glycerol 3‐phosphate. The results are compared with those obtained for the glycerol moiety of phosphatidyl cholines. It is concluded that there is more than one pool of sn‐glycerol 3‐phosphate in the liver, and that the major part has a glycolytic origin.