FUNCTION AND REGULATION OF EICOSANOIDS OF THE LIVER

Within the liver, the resident Kupifer cells and circulating blood cel ls are the main producers of eicosanoids. Major arachidonic acid metab olites produced and released by Kupffer cells are prostaglandin D-2, t hromboxane B-2, prostaglandin E(2) and prostaglandin F-2 alpha. Eicosa noids are removed from liver circulation by the uptake and degradation of hepatocytes. Eicosanoids are capable to increase portal pressure, to reduce liver oxygen uptake, to enhance glycogenolysis and to interf ere with the cellular homeostasis of potassium and calcium. In Kupffer cells prostaglandin E(2) reduces the lipopolysaccharide-induced synth esis and secretion of cytokines but enhances the release of nitric oxi de. The formation of eicosanoids in Kupffer cells is under the control of glucocorticoids, the intracellular pH-value, calcium, cyclic AMP, protein kinase C and albumin.