Determination of the rate of K+ movement through potassium channels in isolated rat heart and liver mitochondria
Determination of the rate of K+ movement through potassium channels in isolated rat heart and liver mitochondria
复制标题
DOI：
10.1016/j.bbabio.2008.04.018
复制
发表时间：
2008-06-01
影响因子：
4.3
通讯作者：
Halestrap, Andrew P.
中科院分区：
文献类型：
--
作者：
Bednarczyk, Piotr;Barker, George D.;Halestrap, Andrew P.
ATP调节的（mitoK（ATP））和大电导钙激活的（mitoBK（Ca））钾通道都被认为调节线粒体K+内流和基质体积，并介导心脏缺血预适应（IP）。然而，这些研究中使用的药理学药物的特异性及其对IP作用的机制仍存在争议。在这里，我们使用增加浓度的K+-离子载体（缬氨霉素）刺激呼吸的大鼠肝脏和心脏线粒体的存在下的K+/H+交换尼日利亚菌素。这允许测定缬氨霉素诱导的K+内流速率，同时平行测量光散射（A（520））和基质体积（（H2O）-H-3和[C-14]-蔗糖），使K+内流速率与基质体积增加相关。光散射很容易检测到K+流入的增加，
Both ATP-regulated (mitoK(ATP)) and large conductance calcium-activated (mitoBK(Ca)) potassium channels have been proposed to regulate mitochondrial K+ influx and matrix volume and to mediate cardiac ischaemic preconditioning (IP). However, the specificity of the pharmacological agents used in these studies and the mechanisms underlying their effects on IP remain controversial. Here we used increasing concentrations of K+-ionophore (valinomycin) to stimulate respiration by rat liver and heart mitochondria in the presence of the K+/H+ exchanger nigericin. This allowed rates of valinomycin-induced K+ influx to be determined whilst parallel measurements of light scattering (A(520)) and matrix volume ((H2O)-H-3 and [C-14]-sucrose) enabled rates of K+ influx to be correlated with increases in matrix volume. Light scattering readily detected an increase in K+ influx of