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胞内Ca~(2+)和小G-蛋白对人中性粒细胞胞吐的调控作用

朱莹, 汪俊汉, 吴健民, 徐涛, 张春光

华中科技大学生命科学与技术学院,生物物理与生物化学研究所.湖北,武汉 430074；华中科技大学本部医院检验科.湖北,武汉 430074；华中科技大学协和医院检验科.湖北,武汉 430030

摘要

钙引起的细胞膜电容增加呈现两个不同的分泌相。第一相发生在钙浓度为0.2--14#mu#mol/L区间,膜电容增加幅度为1.23pF,钙的EC50值为1.1#mu#mol/L。这部分膜电容增加可能对应于三级颗粒的释放。第二相发生在钙浓度为20--70#mu#mol/L区间,膜电容增加幅度为6.36pF,钙的EC50值为33#mu#mol/L。这部分膜电容增加可能对应于一、二级颗粒的释放。细胞内Ca~(2+)浓度可同时影响细胞分泌的平均速率和最终可达到的分泌程度。而用GTP#gamma#S刺激细胞分泌时,只要作用时间足够长(>20min),,20--100#mu#mol/L的GTP#gamma#S均可使中性粒细胞膜电容增加6pF以上。GTP#gamma#S的浓度不影响细胞膜电容的最终可增加的幅度,但细胞分泌的平均速率随着GTP#gamma#S的浓度的增加而增加。

关键词： 中性粒细胞; 胞吐; 钙; 小G-蛋白

Roles of intracellular calcium and monomeric G-proteins in regulating exocytosis of human neutrophils

Zhu Ying, Wang Junhan, Wu Jianmin, Xu Tao, Zhang Chunguang

Institute of Biophysics and Biochemistry,School of Life Science and Technology,Huazhong University of Science and Technology.Wuhan 430074,Hubei；China；Union Hospital,Huazhong University of Science and Technology.Wuhan 430030,Hubei

Abstract

The results showed that the membrane capacitance increase induced by calcium revealed a biphasic process. The first phase occured when the calcium level was between 0.2-14 #mu#mol/L with a plateau amplitude of 1.23 pF and a calcium EC50 of 1.1 #mu#mol/L. This phase might correspond to the release of the tertiary granules. The second phase occured when the calcium concentration was between 20-70 #mu#mol/L with a plateau increment of 6.36 pF, the calcium EC50 being about 33 #mu#mol/L. This phase might represent the release of the primary and secondary granules. Intracellular calcium also simultaneously increased the exocytotic rate and the eventual extent in neutrophils. On the other hand, GTP#gamma#S can increase the exocytotic rate in a dose-dependent manner but had no effect on the eventual extent of membrane capacitance increment (>6 pF) if the cell was stimulated for a long period (>20 min). GTP#gamma#S (ranging from 20 to 100 #mu#mol/L) induced the neutrophils to release all four types of the granules at very low intracellular calcium level.

Key words: Neutrophils;Exocytosis;Calcium;Monomeric

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引用本文：

朱莹, 汪俊汉, 吴健民, 徐涛, 张春光. 胞内Ca~(2+)和小G-蛋白对人中性粒细胞胞吐的调控作用[J]. 生理学报 2003; 55 (6): .

Zhu Ying, Wang Junhan, Wu Jianmin, Xu Tao, Zhang Chunguang. Roles of intracellular calcium and monomeric G-proteins in regulating exocytosis of human neutrophils. Acta Physiol Sin 2003; 55 (6): (in Chinese with English abstract).