A Comparison of the Ketolytic Effect of Succinic Acid with Glucose

Abstract

Korányi and Szent-Györgyi 1 have reported recently that succinic acid given as the calcium salt in daily amounts of 5 to 10 gm. or less is able to decrease the ketosis in diabetics. In the present investigations we have compared the ketolytic action of succinic acid with that of glucose when administered twice daily to fasting male rats weighing approximately 200 gm., in which the endogenous ketonuria was induced by the previous administration of a high butter-fat diet low in protein, as reported earlier. 2 The studies on ketonuria were made on the second to fifth fast days inclusive during which sodium chloride solution (fasting controls), sodium succinate in doses from 9.95 to 149.2 mg. per 100 gm. rat daily, or glucose in equivalent amounts (7.55 to 113.2 mg. per 100 gm. rat) was fed. Urine collections were made daily. The ketonuria of the fasting controls usually rises to a maximum on the third fast day, after which it diminishes rapidly. In Table I a summary of the data is given. No ketolytic effect obtained when as much as 149.2 mg. of succinic acid per 100 gm. rat was given although glucose at a comparable level gave a marked decrease in the acetonuria. This amount of succinic acid on a surface area basis is 50% greater than the largest dose employed by Korányi and Szent-Györgyi. As slight decrease in ketonuria appears when only 7.55 mg. of glucose is given while a dose of 37.8 mg. caused an average decrease of acetone-bodies in the urine from 33.7 mg. per 100 gm. rat in the control tests to 19.4 mg. There was no evidence of diarrhea in any experiments nor of other toxic effects ascribable to the succinic acid.