Intarvin in phlorhizinized dogs.

Abstract

These experiments were undertaken to determine whether intarvin—glyceryl margaric ester—yields extra sugar in the completely phlorhizinized dog. Ringer 1 has shown that propionic acid is quantitatively converted into dextrose in such dogs, and if the β oxidation of saturated normal fatty acids holds, one might expect each molecule of margaric acid to yield one molecule of propionic acid during oxidation in the body. In the phlorhizinized animal this should appear as sugar. 26.8 gm. of intarvin, if pure, could yield 10 gm. of dextrose, assuming that one molecule of the fat would yield one molecule of glycerol and three molecules of propionic acid, and that the glycerol and propionic acid could yield two molecules of dextrose. This calculation takes into consideration the 12 per cent mineral oil added to intarvin but does not allow for the fact that the fat probably is a mixture of about 85 per cent margaric acid and 15 per cent stearic acids combined with glycerol.

Phlorhizin was administered either in olive oil twice a day, or in 1.2 per cent Na₂CO₃ every eight hours, subcutaneously. Dogs were fasted for three days before phlorhizination, and urine discarded until a constant D:N ratio was obtained for a 24 hour control period, then the animal was fed intarvin or butter mixed with lean meat hash and the urine followed for the following 24 hours or until the D:N ratio returned to the figure obtained for the control period. Toluene or NaF (1 per cent) were the preservatives used, nitrogen was determined by Kjeldahl's method, sugar by the Allihn method, total acetone bodies by the VanSlyke method, and organic acids by the method of Van Slyke and Palmer. The dogs were most irregular in acetone body formation, and the results in this field are not felt to be of much value.