Erne P, Mittelholzer E, Bürgisser E, Flückiger R, Bühler F R
J Recept Res. 1984;4(1-6):587-604. doi: 10.3109/10799898409042575.
The intracellular free calcium concentration plays a key role as second messenger in the regulation of cellular reactions. Post-receptor events can be investigated by measurement of free calcium concentration in cells. Our experience in measuring the intracellular free calcium concentration in platelets with the use of the fluorescent indicator quin-2-tetraacetoxymethyl- ester is described. Possible pitfalls in the preparation procedures of the platelets are discussed as well as critical steps and the limitations of the quin-2-method. The methodological approach is demonstrated by the presentation of an investigation with the adenylate cyclase inhibitors adenosine-5'-diphosphate and epinephrine as well as their interrelationship. The potentiation effect of epinephrine to adenosine 5'-diphosphate on platelet function such as aggregation is accompanied by a potentiation of the effect of these two platelet activators in elevating the intracellular free calcium concentration. Adenosine 5'-diphosphate elevates intra-platelet free calcium alone, whereas epinephrine acting through stimulation of the alpha2-receptor needs another permissive factor to immediately elevate the intra-platelet free calcium.
细胞内游离钙浓度作为第二信使在细胞反应调节中起关键作用。受体后事件可通过测量细胞内游离钙浓度进行研究。本文描述了我们使用荧光指示剂喹啉 - 2 - 四乙酰氧基甲酯测量血小板内游离钙浓度的经验。讨论了血小板制备过程中可能存在的问题以及喹啉 - 2法的关键步骤和局限性。通过展示用腺苷酸环化酶抑制剂腺苷 - 5'-二磷酸和肾上腺素进行的研究及其相互关系来阐述该方法。肾上腺素对腺苷 - 5'-二磷酸在血小板功能（如聚集）上的增强作用伴随着这两种血小板激活剂在升高细胞内游离钙浓度方面作用的增强。腺苷 - 5'-二磷酸单独升高血小板内游离钙，而通过刺激α2受体起作用的肾上腺素需要另一个允许因子才能立即升高血小板内游离钙。
