Biphasic increase in intracellular calcium induced by platelet‐activating factor in macrophages

FEBS Letters

Randriamampita, C.¹  Trautmann, A.¹ 

[1] Laboratoire de Neurobiologie, Ecole Normale Supérieure, 46, rue d'Ulm, 75005 Paris, France

关键词: Ca2+;    Fura-2;    Macrophage;    Platelet-activating factor;   

DOI  :  10.1016/0014-5793(89)80624-6

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

In single mouse macrophages stimulated by platelet-activating factor (PAF), the intracellular calcium concentration (Ca_i) monitored with fura-2 at room temperature presents a biphasic increase, including a transient and a more sustained component. After pulse administration of PAF, the first phase lasts for a few seconds and reaches a peak value of 0.5–1 μM Ca²⁺ at high PAF concentration. The amplitude of this peak is independent of extracellular Ca⁺ concentration, suggesting that the initial Ca²⁺ transient is due to the release of Ca²⁺ from intracellular stores. The second phase of the response lasts for several minutes; its maximum amplitude is reached 1–2 min after the brief initial PAF stimulation. This phase, suppressed in zero external Ca²⁺ and increased in 10 mM Ca²⁺, is probably due to influx of Ca²⁺ through the plasma membrane. This secondary Ca²⁺ increase is blocked by 10–50 μM lanthanum. At low PAF concentration, the initial Ca²⁺ transient is not followed by a second phase, showing that the initial rises of Ca²⁺ and of its activator (presumably inositol trisphosphate) are not sufficient to trigger the second phase of Ca²⁺ increase.

【 授权许可】

Unknown