Change in Energy Metabolism of Proliferating Granuloma Tissue in Response to Insulin and 2-Deoxyglucose

Abstract

Change in the energy metabolism following the alteration of glucose utilization at the initial step was examined in the markedly proliferating granuloma tissue induced by the injection of carrageenin in rats. The level of ATP, determined as acid-releasable Pi from charcoal-adsorbed nucleotides and the incorporation of ³²Pi into the ATP fraction were taken as indices of the energy metabolism and their changes were followed after the single or combined administration of insulin, glucose and 2-deoxyglucose. The ATP level was gradually decreased by insulin, while the level was first decreased but then recovered when glucose was concurrently given with insulin. Administration of 2-deoxyglucose induced marked decrease in the ATP level which had already been reduced by overnight fasting to about a third of that in normally fed rats. These facts that the treatments affecting glucose utilization of the cell at the initial step induced marked and prompt changes in the ATP level, indicated that energy metabolism in a proliferating tissue of this kind depended markedly on the continuous flow of glucose utilization, probably glycolysis. No marked change was observed, however, in the ³²Pi incorporation into the ATP fraction, the possible reasons for this being discussed.

Key words

ATP - Energy Metabolism - Granuloma Tissue - Insulin - Glucose Utilization - 2-Deoxyglucose