Influence of a Certain Fraction of Pancreas Lipids on Carbohydrate Metabolism of Depancreatized Dogs. ∗

Abstract

Ever since the demonstration of the internal secretion of the pancreas there have been reports of substances antagonistic to insulin which increase the severity of diabetes. A blood sugar raising fraction of the pancreas reported by Gibbs, Root and MurlinL under the name of glucagon was precipitated by reagents which would precipitate the phospholipids and the cerebroside fractions of the pancreas fats. Further attention has been given recently to the separation of this fraction into its components, A fraction insoluble in acetone and ether, containing therefore the cerebrosides and some sphingomyelin has given some striking effects on the D :N ratios and the R.Q.'s of depancreatized dogs, but no consistent effect on blood sugar. While it does not at this time seem to be identical with the fraction called glucagon in the earlier report, the difference in effects may be due to a difference in dosage. For the time being it will be referred to simply as a diabetogenic fat fraction.

Depancreatized dogs were treated with this fraction by subcutaneous injection. The diabetogenic fraction after precipitation with ether was centrifuged out and suspended in alcohol. The alcohol was then poured into physiological saline and boiled until no odor of alcohol could be detected. Dosage was reckoned by the amount of pig pancreas from which the dose was obtained. With 3 dogs the D:N ratio was markedly increased as shown in Table 1.

The values given are for the 24 hours. The dogs were fed exactly the same on the 2 days. The urine was fractioned into three 4-hour periods and on one 12-hour period. The first 4-hour period (8 a. m. to 12 p. m.) was used as control, the diabetogenic fraction given just after the noon catheterization, and the effects on the metabolism studied in the afternoon. The dogs were fed at 8 p. m. The effect on sugar production and excretion was seen sometimes in the first experimental 4-hr. period, sometimes more plainly in the second, and always in the night period following feeding at 8 p. m.