Fittschen C, Henson P M
Department of Pediatrics, National Jewish Center for Immunology and Respiratory Medicine, Denver, CO 80206.
J Leukoc Biol. 1991 Nov;50(5):517-28. doi: 10.1002/jlb.50.5.517.
The study of factors contributing to secretion of neutrophil azurophil granules has previously been complicated by the inability to induce their release without concomitant exocytosis of specific granules. This publication describes the action of the first two agents, the Na-ionophore monensin and the K-ionophore nigericin which elicited only secretion of azurophil granules. Secretion depended on H+/alkali ion antiport by the ionophores since it was abolished in Na(+)- and K(+)-poor choline buffer. The secretagogue effects of both ionophores did not correlate with changes either in cytoplasmic pH or in transmembrane potential and were not associated with Ca-transients, but were closely associated with azurophil granule alkalinization suggesting that the secretory event resulted from alkali ion/H+ antiport at the granule membrane. Addition of zinc inhibited azurophil (but not specific) granule secretion in response to monensin, CB/FMLP, and zymosan, indicating that secretion induced by these agents shares a common step(s).
以往，由于无法在不伴随特异性颗粒胞吐的情况下诱导嗜天青颗粒的释放，导致对促成嗜天青颗粒分泌的因素的研究变得复杂。本出版物描述了前两种试剂的作用，即钠离子载体莫能菌素和钾离子载体尼日利亚菌素，它们仅引发嗜天青颗粒的分泌。分泌依赖于离子载体的H⁺/碱离子反向转运，因为在缺乏Na⁺和K⁺的胆碱缓冲液中分泌被消除。两种离子载体的促分泌作用与细胞质pH或跨膜电位的变化均无关联，也与Ca²⁺瞬变无关，但与嗜天青颗粒碱化密切相关，这表明分泌事件是由颗粒膜上的碱离子/H⁺反向转运引起的。锌的添加抑制了莫能菌素、CB/FMLP和酵母聚糖诱导的嗜天青（而非特异性）颗粒分泌，表明这些试剂诱导的分泌有一个共同的步骤。
