ANAPHYLATOXIN C5A RECEPTOR MESSENGER-RNA IS STRONGLY EXPRESSED IN KUPFFER AND STELLATE CELLS AND WEAKLY IN SINUSOIDAL ENDOTHELIAL-CELLS BUTNOT IN HEPATOCYTES OF NORMAL RAT-LIVER

Anaphylatoxins (C5a and C3a), which are generated during complement ac tivation, have recently been shown to increase glucose output from hep atocytes (HC) in perfused rat liver, They did not act directly on HC b ut indirectly by prostanoid release from non-parenchymal cells (NPC), probably Kupffer cells (KC). In order to corroborate this mechanism, t he distribution of anaphylatoxin receptors in the different cell types of rat liver was determined by quantitative RT-PCR with primers speci fic for the rat C5a receptor (rC5aR) using RNA isolated from KC, sinus oidal endothelial cells (SEC), hepatic stellate cells (HSC) and HC. In line with functional data, C5aR mRNA was detected in freshly isolated NPC but not in HC of rat liver, Mainly KC but also HSC clearly expres sed C5aR mRNA, while SEC did so only weakly, KC expressed up to 10-fol d more C5aR mRNA than HSC and these in turn up to 10-fold more than SE C, These results support the proposed indirect action of anaphylatoxin s on HC. (C) 1997 Federation of European Biochemical Societies.