论文部分内容阅读
目的和方法： 探讨脑缺血时ＡＴＰ敏感钾（ＫＡＴＰ） 通道的变化，在急性分离大鼠皮层神经元上，分别采取膜片钳技术的细胞贴附式和内面向外式记录方法，观察ＮａＣＮ、ＡＴＰ、乳酸和ｐＨ 诱发的ＫＡＴＰ，单电导多通道电流。结果：ＫＡＴＰ多通道电流，均为外向电流；第一级电流电导与第二级电流电导基本相同，即为单电导多通道电流。贴附式记录时，对照组和ＮａＣＮ多通道电导分别为（９７ ．１６ ±９ ．３２）ｐＳ和（９３ ．４９ ±７．４４）ｐＳ，后者出现概率（３３．３ ％） 明显高于前者（５．４ ％ ）。膜内面向外式记录时，ＫＡＴＰ多通道电流出现概率，实验组（１ μｍ ｍｏｌ／ＬＡＴＰ４１．７％ ，ｐＨ６ ．０ ４０ ．０ ％ ，３０ ｍｍｏｌ／ＬＬａｃｔａｔｅ ５７ ．４ ％） 明显比对照组（２ ．９ ％） 高（ Ｐ＜０ ．０１）；低浓度ＡＴＰ及ｐＨ 降低诱发的多通道电导与对照组一致，均为２００ ｐＳ 左右；而高浓度乳酸诱发的通道电导为２５０ ｐＳ左右，即高浓度乳酸可增大电导（ Ｐ＜０ ．０１） ；而且高浓度乳酸诱发的单电导多通道电流需用高浓度ＡＴＰ（１０ ｍｍｏｌ／Ｌ） 和Ｇｌｉｂ（０．２ ｍ ｍｏｌ／Ｌ） 方能阻断，说明高浓度乳酸可降低ＫＡＴＰ通道对ＡＴＰ的敏感?
Objective: To investigate the changes of ATP-sensitive potassium channel (KATP) in cerebral ischemia rats. Cellular patch-type and inward-facing outward recording methods of patch-clamp technique were used respectively in acutely isolated cortical neurons. NaCN , ATP, Lactate and pH-induced KATP, single-conductance multi-channel currents. Results: KATP multi-channel current, are the outward current; the first-level current conduction and the second-level current conduction is basically the same, that is, single-conduction multi-channel current. Adherent recording, the control group and NaCN multi-channel conductance were (97 .16 ± 9 .32) pS and (93 .49 ± 7.44) pS, the latter was significantly higher than the probability of occurrence (33.3% The former (5.4%). The probability of KATP multi-channel current was significantly higher in the experimental group than in the control group (2 μmol / L ATP4.7%, pH6.040.0%, 30 mmol / L Lactate 57.4%) .9%) (P <0.01). The multi-channel conductance induced by low concentration of ATP and pH was the same as that of the control group, both of which were about 200 pS; while the channel conductivity induced by high concentration of lactic acid was about 250 pS, Concentration of lactic acid increased the conductance (P <0 .01). Moreover, single-conductance multi-channel currents induced by high concentration of lactic acid required higher concentrations of ATP (10 mmol / L) and Glib Off, indicating that high concentrations of lactic acid KATP channel can reduce the sensitivity of ATP?