INSULIN ACTION AND BINDING IN ADIPOCYTES EXPOSED TO ENDOTOXIN INVITRO AND INVIVO

Abstract

In vitro and in vivo effects of [Escherichia coli] endotoxin [etox] on glucose oxidation and insulin binding were investigated in rat adipocytes. Exposure of adipocytes to etox (500 .mu.g/ml) in vitro resulted in 48% increase in basal glucose oxidation after 30 min, 63% and 65% increase after 90 and 150 min, respectively. Adipocytes from rats injected 6 h previously with etox i.v. (2 mg/100 gm) showed elevated (42%) basal glucose oxidation. The absolute levels of stimulation and sensitivity to insulin stimulation were less than in control cells. A tendency for higher insulin binding affinity at low ambient insulin concentrations was noted. At higher insulin concentrations this difference disappeared. An insulin-like effects of etox and perturbation by etox of insulin action at the cellular level were demonstrated. Changes in receptor affinity are suggested. The insulin receptor may be a site for modulation of target cell sensitivity in endotoxemia.