Functional differences between activated and normal rat liver macrophages: LPS uptake capacity by flow cytometric analysis in contrast with TNF-α release

Abstract: Activated liver macrophages are considered to play an important role in the development of liver injuries. Functional differences between activated and normal rat liver macrophages were investigated. In addition, from the therapeutic point of view, the effects of prostaglandin E₁, prostaglandin I₂ and E3330 ((2E)-3-[5-(2,3-dimethoxy-6-methyl-1,4-benzoquinoyl)]-2-nonyl-2-propenoic acid) on the functions of liver macrophages were also determined. Rat liver macrophages were primed by Propionibacterium acnes and activated by a small dose of lipopolysaccharide. Lipopolysaccharide uptake capacity was evaluated quantitatively by flow cytometric analysis. Tumor necrosis factor-α activities were measured by bioassay. There were no significant differences in lipopolysaccharide uptake capacity between activated and normal liver macrophages, while activated liver macrophages had a significantly (P<0.01) higher capacity in the release of tumor necrosis factor-α. Prostaglandin E₁ and E3330 inhibited tumor necrosis factor-α release without suppressing lipopolysaccharide uptake capacity. In this study we have clarified the functional differences between activated and normal liver macrophages. The beneficial effects of prostaglandin E¹ and E3330 on the functions of liver macrophages were also demonstrated.