Hancock J T, Jones O T
Biochem J. 1987 Feb 15;242(1):103-7. doi: 10.1042/bj2420103.
Peritoneal macrophages were elicited in rats by using casein as a stimulus; when stimulated with phorbol 12-myristate 13-acetate (PMA) they produced O2.-. Nearly 60% of the total cytochrome b had a low Em,7.0 of -247 mV, typical of the cytochrome b component found in the NADPH-dependent O2(.-)-generating oxidase of neutrophils. The rate of O2.- generation by macrophages was 1.23 mol of O2.-/s per mol of cytochrome b. Treatment of intact macrophages with diphenyleniodonium (DPI) at 0.9 microM caused 50% inhibition of PMA-induced O2.- generation, with little effect on mitochondrial respiratory activity; KCN inhibited respiratory activity without affecting PMA-induced O2.- generation. A similar specificity of inhibition was found for di-2-thienyliodonium (50% inhibition of O2.- generation at 0.5 microM) and, at higher concentrations, for diphenyl iodonium. When macrophage suspensions were incubated with [125I]DPI followed by autoradiography of SDS/polyacrylamide-gel-electrophoresis-separated polypeptides, radioactivity was most strongly associated with a band of Mr 45,000, similar to that found in neutrophils [Cross & Jones (1986) Biochem. J. 237, 111-116]. The O2(.-)-generating oxidase of macrophages appears to have components in common with the NADPH oxidase of neutrophils, despite differences in activity. Its sensitivity to DPI suggests that selective prevention of radical generation by macrophages in vivo is possible.
通过使用酪蛋白作为刺激物在大鼠中诱导产生腹腔巨噬细胞；当用佛波醇12 - 肉豆蔻酸酯13 - 乙酸酯（PMA）刺激时，它们会产生超氧阴离子（O₂⁻）。总细胞色素b中近60%具有-247 mV的低Em,7.0，这是中性粒细胞中依赖NADPH的O₂⁻生成氧化酶中发现的细胞色素b成分的典型特征。巨噬细胞产生O₂⁻的速率为每摩尔细胞色素b每秒1.23摩尔O₂⁻。用0.9微摩尔的二亚苯基碘鎓（DPI）处理完整的巨噬细胞会导致PMA诱导的O₂⁻生成受到50%的抑制，而对线粒体呼吸活性影响很小；氰化钾抑制呼吸活性但不影响PMA诱导的O₂⁻生成。对于二 - 2 - 噻吩基碘鎓（在0.5微摩尔时对O₂⁻生成有50%的抑制）以及在较高浓度下对于二苯基碘鎓也发现了类似的抑制特异性。当巨噬细胞悬液与[¹²⁵I]DPI孵育，然后对SDS/聚丙烯酰胺凝胶电泳分离的多肽进行放射自显影时，放射性与一条分子量为45,000的条带最强烈相关，这与在中性粒细胞中发现的条带相似[克罗斯和琼斯（1986年）《生物化学杂志》237卷，111 - 116页]。尽管活性存在差异，但巨噬细胞的O₂⁻生成氧化酶似乎与中性粒细胞的NADPH氧化酶有共同成分。其对DPI的敏感性表明在体内选择性预防巨噬细胞产生自由基是可能的。
