| The ischemia/reperfusion of kidney is the most important reason of acute renal failure(ARF) and delayed graft function(DGF), how to prevent ARF and DGF is complicated and incompletely understood and still a hot spot presently. Many studies postulated that the cell ion channels can influence the cell function through special ways, have biovilocent to the cell survive (benefit or harmful), there is at least one potassium channel has an important protection to the cell necrosis and apoptosis after ischemia/reperfusion injury. In epithelial cells of the kidney, K+ channels are primarily involved in maintaining membrane potential, recycling and secreting K+ and regulating cell volume. They are an integral party of cell function in all tubule cells because of their key role in the generation of the cell-negative electrical potential that affects the transmembrane movement of many charged solutes. Significant progress in our understanding of the structure and function of renal K+ channels has become possible by combining several strategies. These include transport studies in single tubules, application of the patch-clamp technique for exploring the properties of single K+ channels in native tubules and the cloning, and expression of diverse K+ channels of renal origin. Insights from these investigations promise to provide a deeper understanding of the mechanism by which K+ channels participate in many diverse tubule functions. However, the physiological role of the potassium channel is poorly understood under the condition of ischemia/reperfusion. In this study we have used the whole patch clamp technique in renal tubular epithelial cells under ischemia/reperfusion conditions. Moreover, we also show that K+ channel activity is extremely sensitive to inhibition by Ba2+. These findings suggest that K+ channels are existed in renal tubular epithelial cells and implicate an important and novel functional role for the kidney ischemia/reperfusion.The main methods:1. We use the subculturing human tubular epithelial cell to build up the similar ischmia/reperfusion injury model.2. We use patch clamp technique to direct measure the membrane K+ channels changes after anoxia and oxidative stress.3. We testified the speculation of TEC energy metabolism changes after anoxia and oxidative stress by traditional methods.4. We use immunofluorescence to detect the cytoskeleton change of TEC. The main results and conclusions were as follows:1 . The energy metabolism changes of TEC after anoxia and oxidative stress :the LDH leakage increase and the activity of Na+-K+-ATPase,Ca2+-ATPase decrease after anoxia and oxidative stress.The results evidence experimental proof which shows the reliability and effectiveness of the similar I/R model.2. The skeleton changes of TEC after anoxia and oxidative stress: The cell skeleton is composed by actin, tubulin, vimentin and destroyed after anoxia and oxidative stress. The results show that the skeleton changes is the substance background and important premise of the structure destroy ,metabolism and function obstacle of TEC.3. Cultured human tubular epithelial cells are easily test by patch clamp technique, the resting membrane potential is, the cascade impedance is 11.58 2.98M , the membrane capacitance is 10.51 ?1.88pF. The converse potential is -40mV,the open time of the channel are obedient the mono-exponent function in mathematics, the two open time constants are 0.653ms and 8.362ms, the close tune of the channel are obedient the bi-exponent function in mathematics, the two close time constants are 1.142ms and 18.924ms. The results prove the K+ channel on TEC be the same as most of K+ channel on different animal species and constitution source.4. The K+ channel changes on TEC after anoxia and oxidative stress: The K+ current amplitude level, density and membrane capacitance of TEC after anoxia and oxidative stress were all remarkably higher than those of normal TEC. The time constant of TEC after anoxia and oxidative stress was significantly smaller than that o...
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