POTASSIUM CHANNELS IN CARDIAC-CELLS ACTIVATED BY ARACHIDONIC-ACID AND PHOSPHOLIPIDS
POTASSIUM CHANNELS IN CARDIAC-CELLS ACTIVATED BY ARACHIDONIC-ACID AND PHOSPHOLIPIDS
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DOI：
10.1126/science.2727703
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发表时间：
1989-06-09
期刊：
影响因子：
56.9
通讯作者：
CLAPHAM, DE
中科院分区：
文献类型：
--
作者：
KIM, D;CLAPHAM, DE
细胞内花生四烯酸或磷脂酰胆碱激活的两种钾选择性激活在新生大鼠的心房细胞中被发现。在由内向外的膜片上，花生四烯酸和磷脂酰胆碱分别开放外向整流钾选择通道，其电导分别为160微微米(Ik.AA)和68微微米(Ik.PC)。这些钾通道对内部应用的三磷酸腺苷(ATP)、镁或钙不敏感。将细胞内pH从7.2降至6.8或6.4可逆地分别使IK.AA通道活性增加三倍或十倍。一些脂肪酸衍生物被测试它们激活IK.AA的能力。这些钾选择性通道可能有助于解释在缺血细胞中观察到的钾电导增加，并增加脂肪酸衍生物作为第二信使的可能性。
Two types of potassium-selective activated by intracellular arachidonic acid or phosphatidylcholine have been found in neonatal rat atrial cells. In inside-out patches, arachidonic acid and phosphatidylcholine each opened outwardly rectifying potassium-selective channels with conductances of 160 picosiemens (IK.AA) and 68 picosiemens (IK.PC), respectively. These potassium channels were not sensitive to internally applied adenosine trophosphate (ATP), magnesium, or calcium. Lowering the intracellular pH from 7.2 to 6.8 or 6.4 reversibly increased IK.AA channel activity three- or tenfold, respectively. A number of fatty acid derivatives were tested for their ability to activate IK.AA. These potassium-selective channels may help explain the increase in potassium conductance observed in ischemic cells and raise the possibility that fatty acid derivatives act as second messengers.