NA;In the past year, data have been published on gene expression of acutehyphen;phase cytokines lpar;interleukinhyphen;1bgr; and interleukinhyphen;6rpar; in healthy human livers. Monokinehyphen;specific messenger RNAs were found in cells of the portal area and of the parenchyma. Identification of the cells, however, was difficult. Three papers addressed the question of the cells responsible for synthesis of acutehyphen;phase mediators during different acutehyphen;phase situations. Surprisingly, Kupffer cells were not found to be the main source of serum tumor necrosis factorhyphen;agr; in two animal models of endotoxinemia. The source of interleukinhyphen;6 synthesis was found to be different depending on the stimulushyphen;inducing acutehyphen;phase reaction in two rat models of acutehyphen;phase reaction. The importance of increased level of acutehyphen;phase mediators in biologic fluids of patients with different liver diseases is still undefined. Some data seem to suggest that increased monokine production is a consequence of liver disease without pathophysiologic importance in the development of liver disease. The importance of local production of the different cytokines during inflammatory processes in the liver is also a matter of debate. The same is true for expression of monokine receptors, as well as expression of adhesion molecules on the surface of the different liver cells. One of the most exciting findings in the pathophysiology of liver fibrogenesis is the partial characterization of a hepatocytic factor called hepitoin, which could be responsible for Itohyphen;cell activation during the preinflammatory stage. Liver regeneration research provided data suggesting that the induction of hepatocyte growth may not be the main function of hepatocyte growth factor. In fact, hepatocyte growth factorhyphen;serum level was found to return to normal levels at a time after hepatectomy in which the regeneration process was not completed. Furthermore, hepatocyte growth factorhyphen;serum level increased after surgery not involving the liver. Along the same line is the finding of a factor called injurin that was detected in the serum of rats after hepatic and nonhepatic damage. Injurin was found to be able to strongly induce hepatocyte growth factorhyphen;synthesis in a human fibroblast cell line. Injurin and hepatocyte growth factor could represent two new acutehyphen;phase mediators.Current Opinion in Gastroenterology 1993,9colon;359hyphen;366
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