Leven R M, Gonnella P A, Reeber M J, Nachmias V T
Thromb Haemost. 1983 Jun 28;49(3):230-4.
The monovalent cation ionophores monensin and nigericin cause platelet shape change at a rate of approximately 1/20 of that caused by ADP. The effect of monensin was studied further. Shape change caused by monensin is pH dependent, increasing in rate as extracellular pH increases. Monensin induced shape change is not blocked by 30 microM cinanserin which completely inhibits serotonin induced shape change. Also, the amount of serotonin secreted by monensin treated platelets is below the threshold required to induce shape change. 100 microM ATP which inhibits ADP induced shape change does not affect monensin induced shape change. Amiloride, a sodium transport blocker, inhibits both the rate of ADP induced shape change and platelet spreading on poly-lysine coated glass. Amorphous platelet cytoskeletons isolated from resting platelets at pH 6.8 with Mg++ but not Ca++ can be transformed into filament bundles by subsequent incubation at pH 7.6. We conclude that platelet shape change is at least in part triggered by changes in cellular Na+ and pH.
单价阳离子离子载体莫能菌素和尼日利亚菌素引起血小板形状改变的速率约为ADP所引起速率的1/20。对莫能菌素的作用进行了进一步研究。莫能菌素引起的形状改变依赖于pH值，随着细胞外pH值升高速率增加。莫能菌素诱导的形状改变不被30微摩尔西那色林阻断，而西那色林可完全抑制血清素诱导的形状改变。此外，经莫能菌素处理的血小板分泌的血清素量低于诱导形状改变所需的阈值。抑制ADP诱导形状改变的100微摩尔ATP不影响莫能菌素诱导的形状改变。钠转运阻滞剂氨氯地平可抑制ADP诱导的形状改变速率以及血小板在聚赖氨酸包被玻璃上的铺展。在pH 6.8、有Mg++但无Ca++的条件下从静息血小板中分离出的无定形血小板细胞骨架，通过随后在pH 7.6下孵育可转化为细丝束。我们得出结论，血小板形状改变至少部分是由细胞内Na+和pH值的变化触发的。
