Experimental models for studying the interaction of kupffer cells and hepatocytes

Hepatic parenchymal cells are estimated to account for 80 to 90° of the total liver cell mass and play a central role in both normal and abnormal physiology and metabolism.1 The nonparenchymal cell (NPC) population that accounts for the remainder of liver cells consists of Kupffer cells (KC) as well as endothelial cells, fat-storing cells, pit cells, and cells of the biliary ductal system. KC make up approximately one third of the NPC population,² and endothelial cells make up the majority of the remaining NPC. KC are the predominant cell type in the fixed macrophage system, and through phagocytosis function prominently in clearing the portal circulation of blood-borne particulate matter, including lipopolysaccharide (LPS).^{3 5} Functional differences exist between KC and other mononuclear phagocytes which have been hypothesized to be due, in part, to their unique position in the hepatic sinusoid. ^5,6 Investigations into the specific factors involved in this unique environment as well as the interaction between parenchymal cells and NPC have been performed for many years.