Yamanishi J, Kawahara Y, Fukuzaki H
Thromb Res. 1983 Oct 15;32(2):183-8. doi: 10.1016/0049-3848(83)90029-4.
With the fluorescent Ca2+ indicator quin2, we measured directly cytoplasmic free Ca2+ [( Ca2+]i) in washed human platelets stimulated by thrombin and examined the effect of cyclic AMP on [Ca2+]i levels and 14C-serotonin release. Thrombin (0.2 U/ml) evoked a rise in [Ca2+]i from the basal level of about 100 nM to integral of 3 microM which was fast enough to trigger serotonin release. This rise was inhibited in a dose-dependent manner by preincubation with prostaglandin E1 (PGE1) (0.1-10 microM) or dibutyryl cyclic AMP (0.01 -1 mM). Parallel to this, serotonin release was also inhibited by these drugs. When added to platelets after stimulation by thrombin, PGE1 caused the rapid decrease of elevated [Ca2+]i. These results provide direct evidence that [Ca2+]i levels in platelets are regulated by cyclic AMP.
我们使用荧光钙指示剂喹哪啶红，直接测量了经凝血酶刺激的洗涤人血小板中的细胞质游离钙浓度（[Ca2+]i），并研究了环磷酸腺苷（cAMP）对[Ca2+]i水平和14C-5-羟色胺释放的影响。凝血酶（0.2 U/ml）可使[Ca2+]i从约100 nM的基础水平升至3 μM的峰值，这一升高速度足以触发5-羟色胺的释放。预先用前列腺素E1（PGE1）（0.1 - 10 μM）或二丁酰环磷酸腺苷（0.01 - 1 mM）孵育，可剂量依赖性地抑制这种升高。与此平行的是，这些药物也抑制了5-羟色胺的释放。在凝血酶刺激血小板后加入PGE1，可使升高的[Ca2+]i迅速降低。这些结果提供了直接证据，表明血小板中的[Ca2+]i水平受环磷酸腺苷调节。
