Findlay I, Faivre J F
Laboratoire de Physiologie Comparée (URA CNRS 1121), Université de Paris XI, Orsay, France.
FEBS Lett. 1991 Feb 11;279(1):95-7. doi: 10.1016/0014-5793(91)80259-6.
We show that ATP-sensitive K+ channels of excised inside-out membrane patches of rat ventricular myocytes show considerable variation in their sensitivity to ATP. In 102 different membrane patches IC50 values ranged from 9 to 580 microM ATP and Hill coefficients from 1% to 6.41% of patches showed openings of ATP-sensitive K+ channels in the presence of 1 mM ATP. These results considerably widen the range of internal ATP concentrations over which one might expect activation of the ATP-sensitive K+ current in cardiac myocytes.
我们发现，从大鼠心室肌细胞分离出的内面向外膜片上的ATP敏感性钾通道对ATP的敏感性存在显著差异。在102个不同的膜片中，IC50值在9至580微摩尔ATP之间，希尔系数在1%至6.41%之间，有1毫摩尔ATP存在时，有一定比例的膜片显示ATP敏感性钾通道开放。这些结果大大拓宽了人们预期可激活心肌细胞中ATP敏感性钾电流的细胞内ATP浓度范围。
