Receptor-activated single channels in intact human platelets.
Receptor-activated single channels in intact human platelets.
复制标题
完整人血小板中受体激活的单通道。
DOI：
10.1016/s0021-9258(18)86972-1
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发表时间：
1990
期刊：
影响因子：
--
通讯作者：
T. Rink
中科院分区：
文献类型：
--
作者：
M. Mahaut;S. Sage;T. Rink
我们报告“细胞贴附”膜片钳研究完整的人血小板显示受体激活的单通道。包括ADP在贴片移液管，但不是在浴缸中，导致在外观的内向电流指示的单通道紧密耦合到ADP受体。通道在静息电位下的斜率电导为11皮西门子。去除1 mM Ca 2+或葡萄糖酸盐在移液管填充溶液中取代氯化物对静息电位下的斜率电导或估计的反向电位几乎没有影响。用等渗氯化钡在移液管中，ADP诱发的单通道电流的斜率电导为10皮西门子。因此，这些通道似乎对一价和二价阳离子是可渗透的，并且相对于阴离子对阳离子具有选择性。向移液管溶液中加入5 mM Ni 2+（其阻断ADP诱发的快速钙进入fura-2加载的血小板）阻断ADP诱发的通道活性。因此，这些通道可能为ADP在一小部分秒内激活人类血小板提供了重要机制。
We report "cell-attached" patch clamp studies of intact human platelets which show receptor-activated single channels. Inclusion of ADP in the patch pipette, but not in the bath, resulted in the appearance of inward currents indicative of single channels tightly coupled to the ADP receptors. The channels had a slope conductance of 11 picosiemens at the resting potential. Removal of 1 mM Ca2+ or replacement of chloride by gluconate in the pipette filling solution had little effect on the slope conductance at the resting potential or on the estimated reversed potential. With isotonic BaCl2 in the pipette, ADP evoked single channel currents with a slope conductance of 10 picosiemens. Thus these channels appear to be permeable to monovalent and divalent cations and selective for cations over anions. Addition of 5 mM Ni2+ (which blocks ADP-evoked rapid calcium entry in fura-2-loaded platelets) to the pipette solution blocked ADP-evoked channel activity. These channels may therefore provide an important mechanism for ADP to activate human platelets within a small fraction of a second.