Weisdorf D J, Thayer M S
Department of Medicine, University of Minnesota Medical School, Mineapolis.
J Lab Clin Med. 1989 Sep;114(3):260-5.
Human neutrophils use divalent cations for the stimulus-response coupling leading to the respiratory burst. We have studied the relevance of the extracellular versus intracellular calcium stores necessary for superoxide generation in neutrophils and neutrophil cytoplasts stimulated by N-formyl-methionyl-leucyl-phenylalanine (FMLP) and phorbol ester and our findings are as follows. (1) FMLP triggered superoxide anion (O2-) generation only in the presence of extracellular calcium, but phorbol myristate acetate (PMA) activation was independent of extracellular calcium. (2) inhibition of calcium transport channels with verapamil produced a dose-related inhibition of FMLP- and PMA-stimulated O2- production. Verapamil inhibition of FMLP-stimulated but not PMA-stimulated O2- was reversed simply by increasing extracellular calcium concentration. Cytosolic calcium loading with substimulatory concentrations of A23187 (0.3 to 0.6 mumol/L) (only in calcium-replete medium) could reverse the verapamil inhibition of PMA-triggered O2- generation. An inhibitor of intracellular calcium availability, 3,4,5-trimethoxybenzoic acid (TMB-8), similarly inhibited FMLP-stimulated and PMA-stimulated O2- production; this inhibition was reversible with A23187 calcium loading. (3) Verapamil, although it inhibited the functional oxidant response, had no inhibitory effect on fura 2-monitored cytosolic calcium rise induced by FMLP stimulation. (4) No cytosolic calcium increment was observed with PMA. O2- generation from enucleated polymorphonuclear leukocyte (PMN) cytoplasts was sensitive to inhibition by verapamil but was less so than O2- generation from intact PMNs. Cytoplasts, nearly depleted of cytoplasmic organelles and cytoskeleton, the potential sites of intracellular calcium stores, were markedly insensitive to the inhibitory effects of TMB-8.(ABSTRACT TRUNCATED AT 250 WORDS)
人类中性粒细胞利用二价阳离子进行刺激 - 反应偶联，从而引发呼吸爆发。我们研究了细胞外与细胞内钙库对于N - 甲酰 - 甲硫氨酰 - 亮氨酰 - 苯丙氨酸（FMLP）和佛波酯刺激的中性粒细胞及中性粒细胞胞质体中超氧化物生成的必要性，结果如下。（1）FMLP仅在细胞外钙存在的情况下触发超氧阴离子（O2-）生成，但佛波醇肉豆蔻酸酯乙酸酯（PMA）激活则不依赖细胞外钙。（2）用维拉帕米抑制钙转运通道会对FMLP和PMA刺激的O2-产生产生剂量相关的抑制作用。维拉帕米对FMLP刺激而非PMA刺激的O2-的抑制作用可通过增加细胞外钙浓度简单逆转。用亚刺激浓度的A23187（0.3至0.6μmol/L）（仅在钙充足的培养基中）进行胞质钙加载可逆转维拉帕米对PMA触发的O2-生成的抑制作用。细胞内钙可用性抑制剂3,4,5 - 三甲氧基苯甲酸（TMB - 8）同样抑制FMLP刺激和PMA刺激的O2-产生；这种抑制作用可通过A23187钙加载逆转。（3）维拉帕米虽然抑制了功能性氧化剂反应，但对FMLP刺激引起的用fura 2监测的胞质钙升高没有抑制作用。（4）PMA未观察到胞质钙增加。无核多形核白细胞（PMN）胞质体产生的O2-对维拉帕米抑制敏感，但比完整PMN产生的O2-敏感性低。胞质体几乎耗尽了细胞质细胞器和细胞骨架，而细胞骨架是细胞内钙库的潜在位点，对TMB - 8的抑制作用明显不敏感。（摘要截断于250字）
