An effect of liver extracts on glucose tolerance in rats

¹ Section on Experimental Liver Diseases, National Institute of Arthritis and Metabolic Diseases, National Institutes of Health, Bethesda, Maryland

The effect of liver extracts on glucose tolerance of intact and eviscerated rats deficient in glucose tolerance factor (GTF) was investigated. Extracts prepared from livers of rats on a wheat-casein ration restored impaired glucose tolerance of GTF-deficient rats to normal with doses of 250–500 µg dry weight per 100 g weight, whereas similar preparations from kidney and spleen were ineffective. Infusion of the liver fraction (.6 mg/hr) increased glucose tolerance of eviscerated rats from about 45 mg to over 70 mg of glucose per 100 g per hour. The results indicate the presence of an active principle which is water soluble, heat stable, and different from GTF. While strongly enhancing the disposal of excess glucose, it does not affect normal blood sugar levels of fasting animals.