KUPFFER CELLS CYTOTOXICITY AGAINST HEPATOMA-CELLS IS RELATED TO NITRIC-OXIDE

We have previously demonstrated that rat resting macrophages have cyto toxicity against tumor cells. In the current study we have performed a n in vitro experiment to explore the mechanism of Kupffer cells-mediat ed cytotoxicity against hepatomas. The coculture of tumor cells with K upffer cells (derived from rat livers) stimulated syngeneic and alloge neic Kupffer cells to produce nitric oxide. Kupffer cell-mediated cyto toxicity was paralleled to the amount of nitric oxide and was abolishe d by the addition of N-G-monomethyl-L-arginine. The ability to stimula te Kupffer cells to produce nitric oxide resided on the membranous fra gment of tumor cells. (C) 1994 Academic Press, Inc.