Eicosanoid Production in Nonparenchymal Liver Cells Isolated From Rats Infused With E. coli Endotoxin

Abstract

Continuous i.v. infusion of a nonlethal dose of Escherichia coll endotoxin induced an early (3-h) accumulation of neutrophils in the rat liver followed by a later (30-h) greater extravasation of mononuclear phagocytes (MNP). These inflammatory cells, recovered together by centrifugal elutriation, were analyzed for their potential capacity to metabolize [1-¹⁴C]-AA. Ca²⁺ ionophore A23187 (5 μM) stimulated the release of [1-¹⁴C]-AA from PC and PI both in cells from saline- and ET-infused rats, the latter showing a higher capacity to further metabolize AA to eicosanoids. LTB₄ and 5-HETE were the major metabolites accumulated in cells from rats infused with ET for 3 h, while PGD₂ played the main role in cells from saline-infused rats. This could reflect [1-¹⁴C]-AA metabolism by PMNP and Kupffer cells, respectively. By 30 h of ET-infusion, a shift from PGD₂ to PGE₂ release was observed. These results suggest that eicosanoids released by nonparenchymal cells (i.e., Kupffer and endothelial cells) and PMNP in the liver of ET-infused rats may alter the normal intercellular information flow between parenchymal and nonparenchymal cells, contributing to the severe impairment in liver function and metabolism during endotoxicosis and sepsis.