Ward P A, Cunningham T W, Johnson K J
Department of Pathology, University of Michigan Medical School, Ann Arbor 48109.
Clin Immunol Immunopathol. 1989 Jan;50(1 Pt 1):30-41. doi: 10.1016/0090-1229(89)90219-5.
When rat neutrophils were stimulated with chemotactic peptide N-formyl-Met-Leu-Phe; fMLP), phorbol myristate acetate (PMA), or immune complexes in the presence of homologous platelets, O2- responses were enhanced. Secretion products of thrombin-stimulated platelets as well as ATP, ATP gamma S, or ADP enhanced O2- responses of fMLP-stimulated neutrophils, although these nucleotides did not, by themselves, initiate an O2- response. Calcium transients were measured in neutrophils which were stimulated with fMLP under a variety of conditions (+/- ATP gamma S, +/- cytochalasin B) which enhance O2- responses. Neutrophils incubated with ATP gamma S alone developed brief calcium transients similar to those produced by fMLP. As compared to changes in intracellular calcium in fMLP-stimulated neutrophils, the copresence of ATP gamma S with fMLP did not cause a statistically significant difference in the calcium transients, even though O2- production was enhanced. In contrast, in the presence of cytochalasin B, the addition of ATP gamma S to fMLP-stimulated neutrophils produced greatly sustained and protracted elevations in intracellular calcium, correlating with further enhancement of O2- responses. In fMLP-stimulated neutrophils the latter phases of the calcium transients appeared to be dependent in part on the availability of extracellular calcium. These data suggest that ATP gamma S-induced enhancement of O2- responses in fMLP-stimulated rat neutrophils may be related to two mechanisms, one being independent of fMLP-induced intracellular calcium transients and the other, which is related to the presence of cytochalasin B, being linked to sustained elevations in intracellular calcium associated with mobilization of extracellular calcium.
当在同源血小板存在的情况下，用趋化肽N-甲酰基-蛋氨酸-亮氨酸-苯丙氨酸（fMLP）、佛波酯（PMA）或免疫复合物刺激大鼠中性粒细胞时，超氧阴离子（O₂⁻）反应增强。凝血酶刺激的血小板分泌产物以及ATP、ATPγS或ADP增强了fMLP刺激的中性粒细胞的O₂⁻反应，尽管这些核苷酸本身不会引发O₂⁻反应。在多种增强O₂⁻反应的条件下（±ATPγS、±细胞松弛素B），用fMLP刺激中性粒细胞并测量钙瞬变。单独用ATPγS孵育的中性粒细胞会产生短暂的钙瞬变，类似于fMLP产生的钙瞬变。与fMLP刺激的中性粒细胞内钙的变化相比，ATPγS与fMLP共同存在时，钙瞬变没有统计学上的显著差异，尽管O₂⁻产生增加了。相反，在细胞松弛素B存在的情况下，向fMLP刺激的中性粒细胞中添加ATPγS会使细胞内钙持续大幅升高，这与O₂⁻反应的进一步增强相关。在fMLP刺激的中性粒细胞中，钙瞬变的后期似乎部分依赖于细胞外钙的可用性。这些数据表明，ATPγS诱导的fMLP刺激的大鼠中性粒细胞中O₂⁻反应增强可能与两种机制有关，一种与fMLP诱导的细胞内钙瞬变无关，另一种与细胞松弛素B的存在有关，与细胞内钙的持续升高以及细胞外钙的动员有关。
