Experimental isovalthinuria. Ⅱ. Experiment with isovaleric acid-1-C14

To verify whether the administered isovaleric acid does directly incorporate into urinary isovalthine or not, a young male dog was given labeled isovaleric acid-1-C14 (0.2 mc.) and the urinary isovalthine was analyzed by means of paper electrophoresis and column chromatography. Observations proved that isovalthine appeared in urine but showed no radioactivity while glutamic acid gave a strong activity. The possible metabolic pathway of isovaleric acid has been discussed.