TUMOR-NECROSIS-FACTOR INCREASES INVIVO GLUCOSE-UPTAKE IN HEPATIC NONPARENCHYMAL CELLS

This study aims to elucidate the in vivo metabolic response of different liver cells following a short-term (30 min) infusion of a nonlethal dose of human recombinant tumor necrosis factor (TNF). In vivo glucose uptake of different tissues and isolated liver cells was determined by a sequential double-labeling version of the tracer 2-deoxyglucose technique. Following TNF administration glucose uptake was increased in the liver, lung, spleen, and skin while it was not changed in muscle and testis. In response to TNF infusion neutropenia developed which was sustained for 40 min. The number of lymphocytes in the blood was also decreased after the termination of TNF infusion. This short-term infusion of TNF, however, was not accompanied by marked sequestration of leukocytes into the liver. In vivo glucose uptake in response to TNF was doubled in the Kupffer cells and increased by 56% in hepatic endothelial cells. Glucose uptake of parenchymal cells was not significantly affected. The prompt increase of glucose uptake in the reticuloendothelial cells of the liver, primarily in the Kupffer cells, following TNF administration suggests that a similar metabolic response of these cells to sepsis may be mediated at least in part by TNF. It is suggested that the increased glucose uptake by the hepatic nonparenchymal cells is a reflection of the immunmodulatory effect of TNF.