Stolarek Robert, Białasiewicz Piotr, Nowak Dariusz
Department of Experimental and Clinical Physiology, Institute of Physiology and Biochemistry, Medical University of Lodz, Mazowiecka str 6/8, 92-215 Lodz, Poland.
Pulm Pharmacol Ther. 2002;15(4):385-92. doi: 10.1006/pupt.2002.0369.
The evidence of the effect of N-acetylcysteine on reactive oxygen species produced by human polymorphonuclear leukocytes (PMNs) is often contradictory, as thiol compounds may react with not only reactive oxygen and nitrogen species but also they may influence intracellular glutathione levels. The effect of 20, 100 and 200 microM N-aceylcysteine (NAC) on luminol dependent chemiluminescence (LDCL) of human PMNs (10(6) cells/ml phospate buffered saline (PBS)) and whole blood to N-formyl-methionyl-leucyl-phenylalanine (fMLP) and phorbol-12-myristate-13-acetate (PMA) was studied. Further, the ability of NAC to increase PMNs intracellular thiols and affect subsequent PMNs, stimulation was assessed. NAC 100 and 200 microM, but not 20 microM, was found to attenuate the kinetic parameters of initial phase of fMLP-stimulated PMNs oxidative burst. NAC at the concentration of 100 and 200 microM decreased the rate, maximum and integrated value of PMNs response to fMLP. The integrated value of PMA-induced PMNs and fMLP-induced whole blood LDCL response was also decreased by 100 and 200 microM NAC. Furthermore, all tested NAC concentrations decreased LDCL of resting PMNs suspension. The chemiluminescence pattern of reactive oxygen species (ROS) generation by PMNs stimulated with fMLP or PMA did not differ significantly from those preincubated with either 20, 100, or 200 microM NAC. Similarly, NAC did not increase the concentration of intracellular thiols in resting PMNs. However, addition of 200 microM NAC to PMA-stimulated PMNs prevented the decline in intracellular thiols pool. Both PMA- and fMLP-activated PMNs oxidized extracellular NAC. These results indicate that NAC decreases the intensity of PMNs oxidative burst by direct scavenger activity.
N-乙酰半胱氨酸对人多形核白细胞（PMN）产生的活性氧的影响证据常常相互矛盾，因为硫醇化合物不仅可能与活性氧和氮物种发生反应，还可能影响细胞内谷胱甘肽水平。研究了20、100和200微摩尔N-乙酰半胱氨酸（NAC）对人PMN（10⁶细胞/毫升磷酸盐缓冲盐水（PBS））和全血对N-甲酰甲硫氨酰亮氨酰苯丙氨酸（fMLP）和佛波醇-12-肉豆蔻酸酯-13-乙酸酯（PMA）的鲁米诺依赖性化学发光（LDCL）的影响。此外，评估了NAC增加PMN细胞内硫醇并影响随后PMN刺激的能力。发现100和200微摩尔的NAC可减弱fMLP刺激的PMN氧化爆发初始阶段的动力学参数，而20微摩尔的NAC则无此作用。100和200微摩尔浓度的NAC降低了PMN对fMLP反应的速率、最大值和积分值。100和200微摩尔的NAC也降低了PMA诱导的PMN和fMLP诱导的全血LDCL反应的积分值。此外，所有测试的NAC浓度均降低了静息PMN悬液的LDCL。用fMLP或PMA刺激的PMN产生活性氧（ROS）的化学发光模式与用20、100或200微摩尔NAC预孵育的PMN的化学发光模式无显著差异。同样，NAC也未增加静息PMN中细胞内硫醇的浓度。然而，向PMA刺激的PMN中添加200微摩尔NAC可防止细胞内硫醇池的下降。PMA和fMLP激活的PMN均氧化细胞外NAC。这些结果表明，NAC通过直接清除剂活性降低了PMN氧化爆发的强度。
