摘要
本工作对肾小管细胞基侧膜上钾离子通道的活动进行初步的探讨。实验通过体视显微镜直视下从大鼠肾脏冠状切片中机械分离出肾小管 ,采用cell attached膜片单通道实验技术 ,观测肾小管细胞基侧膜钾离子通道活动及pH值对其的影响。结果表明 ,大鼠肾小管细胞基侧膜上广泛分布一类低电导的钾离子通道 ,该通道在超极化状态下表现为内向电流 ,斜率电导为 2 8 2± 1 7pS ,通道开放活动随极化程度的增大而增加。在反极化状态下表现为外向电流 ,且具有内向整流特性 ,其外向电流的弦电导为 5 6± 0 3pS。该通道对四乙胺不敏感 ,但可被优降糖所抑制。通道的活动受细胞外液pH值的影响 。
The potassium channel on the basolateral membrane of renal proximal tubule in rat was studied. Nephrons were dissected from rat kidney with no preliminary enzyme treatment in a stereoscopic microscope. The standard configuration for single channel tight seal patch clamp technique was used to record channel currents from the basolateral membrane. The potassium channel spontaneous current was recorded in the most cell attached patches as the gigaohm seal was formed. The basolateral membrane K + channel appeared to be an inward rectifier. The channel activity increased with hyperpolarization. The limiting inward slope conductance was 28.3±1.7 pS (Vp is between 40 mV and 80 mV, n=6) and the outward chord conductance was 5.6±0.3 pS (Vp is between -40 and -60 mV, n=5). The channel is not sensitive to tetraethylammonium but was inhibited by glibenclamide. The opening probability of the channel decreased when the extracellular fluid was acidulated.
出处
《基础医学与临床》
CSCD
北大核心
2003年第2期216-219,共4页
Basic and Clinical Medicine
关键词
肾小管细胞
基侧膜
钾离子通道
大鼠
kidney tubule
basolateral membrane
potassium channel
