productionby spontaneouslytransformed hamster fibroblasts

摘要: Nitric oxide has been implicated as an important elTector molecule involved in tumor cell growth and cytotoxicity. In these studies we examined mechanisms regulating nitric production by hamster cells. Cocultures of alveolar macrophages (HAM) spontaneously transformed embryonic fibroblasts (STHE cells) pro- duced significant quantities response to lipopolysaccharide (LPS). Culture supernatants from l1A1�1 treated with LPS also stimulated STHE cells, whereas culture had no effect on HAM. These data, together the findings that paraformalde- hyde treatment STilE but not macrophages, completely abrogated cocultures demonstrate cells were source this mediator. contrast STHE-83/20 a highly malignant variant, did produce HAM or even presence LPS. Both anti-tumor necrosis factor-a (TNF-a) anti- interleukin-la (IL-la) antibodies inhibited HAM-in- However, kinetics their effects different. Moreover, although stimulating activ- ity 11AM was anti-TNF-a antibody, it only minimally reduced anti-IL-la antibody. data TNF-a IL-la play distinct roles induction synthesis found suppress proliferation NQmonomethyl-L-argmine, which blocks synthase. Abrogation macrophage-induced cytostasis antibody associated decreased production. Thus released may indirectly activate for suppressing proliferation. J. Leukoc. Biol. 60: 473-479; 1996.