Further characterization of a model of chronic endotoxemia in the rat: adenine nucleotide content in liver.

Abstract

Male Sprague-Dawley rats (320-380 g) were treated with Escherichia coli endotoxin (ET) either acutely (3 and 4.5 mg/100 g b.w.,) or chronically (0.1 mg/100 g b.w./24 h, i.v. from subcutaneously implanted osmotic pumps). Control rats received only sterile saline. At 6 h after injection and after 30, 54, 126, and 198 h of continuous ET infusion, the animals were sacrificed, and adenine nucleotide content in liver was assayed. Acute ET treatment with either dose produced a slight decrease in ATP content (15% and 11% with 3 mg and 4.5 mg ET/100 g b.w., respectively) associated with an increase of ADP and AMP content and a fall of the energy charge (by 9.2% and 6.4%, with the two ET doses, respectively). Chronic ET treatment did not affect either of the measured parameters. However, in both saline- and ET-infused rats a decrease of ATP content paralleled by an increased level of ADP and AMP and by a fall of energy charge were seen when compared to acutely saline-injected rats. Such changes can be attributed to the surgical trauma associated with pump implantation. It is concluded that the energy status of the liver during endotoxemia cannot account for metabolic disturbances associated with this pathophysiological state.