两种肿瘤细胞株对小鼠腹腔巨噬细胞产生一氧化氮的影响

The Influence of Two Tumor Cell Lines on Nitric Oxide Production from Peritoneal Macrophages in Mice

目的：研究体外两种肿瘤细胞株对巨噬细胞（M）产生一氧化氮（NO）的影响。方法：在培养的各组小鼠腹腔巨噬细胞中．分别加入10％、25％和50％浓度的培养18h的HepA腹水型肝癌，及EAC瘤细胞培养混悬液或其条件培养液（即上清液）．24h后观察M上清液中NO的产生量；同时对50％浓度瘤细胞条件培养液作用24h后的M中的一氧化氮合成酶（NOS）进行组化染色。结果：HepA瘤细胞培养混悬液及其条件培养液均能明显地促进M产生NO（P＜0．01）。EAC瘤细胞条件培养液在10％和25％浓度时，对M产生NO无明显影响（P＞0．05），但在50％浓度时却表现明显的抑制作用（P＜0．05）。EAC瘤细胞培养混悬液在10％和25％浓度时明显促进M产生NO（P＜0．01）；而在50％浓度时，其促进作用不明显．且与其10％和25％浓度组比较，有显著性差异（P＜0．01）。NOS染色结果表明，经50％EAC条件培养液作用的M．其NOS阳性表达弱于对照组；而经50％HePA条件培养液作用之M，其NOS阳性表达强于对照组。结论：不同肿瘤对巨噬细胞产生NO具有不同影响，并与瘤细胞或其分泌因子的浓度有关。

Objective To study the influence of two tumor cell lines on nitric oxide (NO) production ofmacrophages in vitro. Methods: Culture mixture or conditioned medium (supernatant) of HepA and EAC tumorcells (for 18 h ) was added to cultured macrophages at concentrations of 10%. 25 % and 50% respectively. After24 h, NO levels in supernatants of macrophages were measured. Nitric oxide synthase (NOS) in macrophagescultured with 50% concentration of tumor cells conditioned medium were stained by histochemical method. Results: Both culture mixture and its conditioned medium of HepA tumor cell remarkably increased NO productionof macrophage (P<0. 01 ). Conditioned medium of EAC tumor cells showed no remarkable effect on NO production at 10% and 25% concentrations, but remarkably decreased NO production at 50% concentration. NOSexpression in macrophages treated with 50% EAC tumor cell conditioned medium was weaker than that of control, while NOS expression was stronger treated with 50% HepA cell conditioned medium. Conclusion: Theseresults suggest that different kinds of tumor have different effects on NO production of macrophage, and theseeffects may be related to concentrations of tumor cells or their secretions.