Comparison of [3H]Bepridil and [3H]Verapamil Uptake into Rabbit Aortic Rings
Comparison of [3H]Bepridil and [3H]Verapamil Uptake into Rabbit Aortic Rings
复制标题
兔主动脉环摄取[3H]苯普地尔和[3H]维拉帕米的比较
DOI：
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发表时间：
1982
影响因子：
3
通讯作者：
N. Sperelakis
中科院分区：
文献类型：
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作者：
S. Mras;N. Sperelakis
研究了~(3 H)Ca拮抗剂在兔离体主动脉环上的外流和摄取。[~3H]苯丙地尔的外排是从两个隔室进行的。较快的初始间隔(T12-0.6分钟)可能代表细胞外空间的外流。较慢的成分(T12=25min)可能反映了细胞间隙的外流。细胞摄取[~3H]苯丙地尔的初始速率为0.001 pmoL/S·cm~2，80min后摄取达到稳定状态。当钙离子浓度增加到正常的4倍时，[~3H]苯普地尔摄取显著下降，提示钙离子与苯普地尔之间可能存在竞争。然而，将Ca~(2+)浓度降至1/4正常时，[~3H]苯丙地尔摄取略有下降。除非洋地黄素处理破坏细胞膜，否则维拉帕米不会被组织明显摄取(低于[~3H]苯丙地尔摄取量的100%)。(将钙离子浓度降至正常的四分之一略有增加[~3H]维拉帕米的摄取量。)这些数据表明，苯普地尔可以穿过肌膜(因此可能产生一些内部效应)，而维拉帕米则被细胞膜有效地排除在细胞内部。
Summary The efflux and uptake of (3H]Ca antagonists were studied in isolated rings of rabbit aorta. The efflux of [3H]bepridil occurred from two compartments. The faster (T12 - 0.6 min) initial compartment presumably represented efflux from the extracellular space. The slower (T12 = 25 min) component probably reflected efflux from the intracellular space. The uptake of [3H]bepridil into the cells occurred at an initial rate of 0.001 pmol/s - cm2, and by 80 min, uptake had reached steady state. Increasing the Ca2 concentration to four times normal caused a marked decrease in the [3H]bepridil uptake, implying a possible competition between Ca2+ and bepridil. However, decreasing the Ca2+ concentration to one-fourth normal caused a slight decrease in [3H]bepridil uptake. [3H]Verapamil was not appreciably taken up by the tissues (less than 100% of [3H]bepridil uptake) unless the cell membranes were disrupted by digitonin treatment. (Lowering the Ca2+ concentration to one-fourth normal slightly increased [3H]verapamil uptake.) These data suggest that bepridil can cross the sarcolemma (and therefore may exert some internal effect), whereas verapamil is effectively excluded from the cell interior by the cell membrane.