Henson P M, Zanolari B, Schwartzman N A, Hong S R
J Immunol. 1978 Sep;121(3):851-5.
Human neutrophils released the granule constituents myeloperoxidase and lysozyme, but not the cytoplasmic enzyme lactic dehydrogenase, when pretreated with cytochalasin B and stimulated with purified human C5a. Prior exposure to C5a before the cytochalasin B, however, abrogated the subsequent secretory process. Interaction of neutrophils with C5a was shown to result in a concentration-dependent rapid desensitization that could not be overcome by later addition of cytochalasin B or of cytochalasin B and C5a. The effect was relatively stimulus specific in that neutrophils desensitized in this manner could be induced to release granule enzymes by casein or by complement-coated zymosan particles. Cytochalasin B effects on neutrophils appear to mimic those of surface binding of soluble stimuli such as C5a and immune complexes. It is suggested that desensitization in concert with surface stimulation may represent an important intracellular mechanism for limiting neutrophil secretion.
当用细胞松弛素B预处理并用人纯化C5a刺激时，人中性粒细胞释放颗粒成分髓过氧化物酶和溶菌酶，但不释放细胞质酶乳酸脱氢酶。然而，在细胞松弛素B处理之前先接触C5a，则会消除随后的分泌过程。已表明中性粒细胞与C5a的相互作用会导致浓度依赖性的快速脱敏，随后添加细胞松弛素B或细胞松弛素B与C5a都无法克服这种脱敏。这种效应相对具有刺激特异性，因为以这种方式脱敏的中性粒细胞可被酪蛋白或补体包被的酵母聚糖颗粒诱导释放颗粒酶。细胞松弛素B对中性粒细胞的作用似乎模拟了可溶性刺激物（如C5a和免疫复合物）表面结合的作用。有人提出，与表面刺激协同作用的脱敏可能是限制中性粒细胞分泌的一种重要细胞内机制。
