Wickramasinghe S N, Barden G, Gardner B
Department of Haematology, St, Mary's Hospital Medical School, Imperial College of Science, Technology & Medicine, University of London, UK.
Clin Lab Haematol. 1991;13(1):41-50. doi: 10.1111/j.1365-2257.1991.tb00250.x.
Solutions containing 5,5-diphenyl[4-14C]hydantoin (15 micrograms/ml) or pheno[2-14C]barbital (20 micrograms/ml) were incubated for 0.5-6 h with monolayers of unstimulated and phorbol-ester-stimulated human blood-monocyte-derived macrophages and suspensions of K562 cells. The incubated solutions were centrifuged and the cell-free supernatants subjected to chromatography on Q-Sepharose Fast Flow anion exchange resin. The interaction with unstimulated macrophages but not with K562 cells resulted in a time-dependent conversion of the original radioactive drug molecules to molecules with a larger negative charge in the case of diphenylhydantoin and a smaller negative charge in the case of phenobarbital. These conversions were prevented by 20 mM tetrahydrofurane and partially inhibited by 300 U/ml superoxide dismutase (SOD) and, therefore, appeared to depend on cytochrome-P-450-mediated reactions and to some extent also on superoxide anion radicals. Macrophages which were stimulated by 20 nM phorbol myristate acetate metabolized both drugs at much faster rates than unstimulated macrophages. Since this increased metabolism was abolished in the presence of SOD, it appeared to be entirely dependent on superoxide anion radicals. These data provide biochemical evidence that unstimulated human monocyte-derived macrophages have a substantial capacity to metabolize certain xenobiotics and that stimulated macrophages have an even greater capacity to do so. This property of macrophages may have considerable biological significance and be important in the pathogenesis both of drug-induced tissue damage and of malignant disease.
含有5,5 - 二苯基[4 - ¹⁴C]海因（15微克/毫升）或苯[2 - ¹⁴C]巴比妥（20微克/毫升）的溶液，分别与未刺激的和佛波酯刺激的人血单核细胞衍生巨噬细胞单层以及K562细胞悬液孵育0.5 - 6小时。孵育后的溶液经离心处理，无细胞上清液在Q - Sepharose Fast Flow阴离子交换树脂上进行层析。与未刺激的巨噬细胞相互作用而非与K562细胞相互作用，导致在二苯基海因的情况下，原始放射性药物分子随时间转化为带更大负电荷的分子；在苯巴比妥的情况下，则转化为带更小负电荷的分子。这些转化被20 mM四氢呋喃阻止，并被300 U/ml超氧化物歧化酶（SOD）部分抑制，因此似乎依赖于细胞色素P - 450介导的反应，并且在一定程度上也依赖于超氧阴离子自由基。用20 nM佛波醇肉豆蔻酸酯刺激的巨噬细胞代谢这两种药物的速度比未刺激的巨噬细胞快得多。由于在SOD存在下这种增强的代谢被消除，所以它似乎完全依赖于超氧阴离子自由基。这些数据提供了生化证据，表明未刺激的人单核细胞衍生巨噬细胞具有代谢某些外源性物质的显著能力，而刺激后的巨噬细胞具有更强的代谢能力。巨噬细胞的这一特性可能具有相当大的生物学意义，并且在药物诱导的组织损伤和恶性疾病的发病机制中都很重要。
