INTERLEUKIN-6 SECRETION IN MICE IS ASSOCIATED WITH REDUCED GLUCOSE-6-PHOSPHATASE AND LIVER-GLYCOGEN LEVELS

Mice bearing interleukin-6 (IL-6)-secreting tumor were used to study t he chronic effect of IL-6 on carbohydrate metabolism. Mice were inject ed with allogeneic tumor cells transduced with the murine IL-6 gene. S erum IL-6 levels were correlated exponentially with tumor weight. Secr etion of IL-6 from the developed tumors was associated with decreased food consumption, reduced body weight, and reduced blood glucose level s. Insulin levels did not change, and 2-deoxyglucose uptake was not af fected in most tissues examined. A significant increase of 2-deoxygluc ose uptake was measured in the liver. Glycogen content in the liver de termined 0, 6, 12, and 18 days after tumor inoculation was 42, 23, 12, and 3 mg/g, respectively. The activity of phosphoenolpyruvate carboxy kinase was not affected. The activity of glucose-6-phosphatase (G-6-Pa se) determined 6, 12, and 18 days after tumor injection was 84, 70, an d 50% of G-6-Pase activity in pair-fed mice bearing nonsecreting tumor s, respectively. G-6-Pase mRNA levels were markedly reduced due to inh ibition of G-6-Pase gene transcriptional rate.