Lung water accumulation in rats after repeated challenges of a sublethal dose of E. coli and its relation to the hepatic energy charge.

Abstract

We produced a septic model of rats in which lung water accumulation was developed. The degree of lung water accumulation was then compared with the hepatic energy status because the liver is not only a metabolic central organ but also one of the central organs of the reticulo-endothelial system (RES), and clinically, lung edema in sepsis seems to relate to failure of the RES. Three experimental models were examined to form lung water accumulation, namely: the lethal model, given E. coli 6.0 X 10(6) CFU/g BW, the sublethal model, given E. coli 2.0 X 10(6) CFU/g BW, and the repeated sublethal dose injection model, given E. coli 2.0 X 10(6) X 2 at 12 hour intervals. In the lethal models, the energy charge (EC) of the liver decreased markedly (p less than 0.001) without recovery and the lung water accumulated (p less than 0.05). In the sublethal models, EC decreased transiently (p less than 0.05) and the lung water did not increase. However, when the microbial challenge with a sublethal dose was repeated, the decreases in EC were prolonged and the lung water increased significantly after the second injection (p less than 0.001) despite a 4.9 per cent mortality during the subsequent 24 hours. It is suggested that when the decrease in liver EC is prolonged, even if it is not fatal, an accumulation of lung water is possible in septic states. This finding may help further analyses of the interrelationship between the lung and the liver in severely infected patients.