DIFFERENTIAL EXPRESSION OF CYTOKINE GENES IN MONOCYTES, PERITONEAL-MACROPHAGES AND LIVER FOLLOWING ENDOTOXIN-INDUCED OR TURPENTINE-INDUCED INFLAMMATION IN RAT

Pro-inflammatory cytokines are produced after systemic or local inflam mation by a wide variety of cell types including monocytes, macrophage s, Kupffer and endothelial cells. Previous studies have shown that IL- 6 gene expression does not occur in liver from rats undergoing an acut e phase response after turpentine injection or controls. These data do not rule out the possibility that delivery of a pathogen to the liver via the portal circulation could directly activate the Kupffer cells, Rats were injected either intravenously or intraperitoneally with LPS , or subcutaneously with turpentine oil, The changes in IL-1 beta, IL- 6, and TNF mRNA levels in monocytes (collected from portal vein or cav al cein), peritoneal macrophages and liver over a 3-hour period post-t reatment were examined. The kinetics of LPS- vs turpentine-induced cyt okine mRNAs in these various cell types were compared by quantitative reverse transcription and polymerase chain reaction (RT-PCR). Our data demonstrate that an intrahepatic expression of cytokines in the non p arenchymal cells was induced by an LPS challenge but not by a turpenti ne-induced inflammation. This process could act as a paracrine mechani sm in the acute-phase response and play a role in the modulation of he patic regeneration. (C) 1996 Academic Press Limited