【摘要】 目的:观察不同浓度葛根素对大鼠海马CA1区锥体细胞L型钙离子通道的作用。方法:采用酶加机械分离的方法,急性分离出成年大鼠海马CA1区锥体细胞后,将含有锥体细胞的细胞悬液滴加于盖玻片上,待贴壁后选取符合实验条件的细胞,运用膜片钳单通道技术记录同一钳制电压下离子通道活动情况。结果:低浓度葛根素(1.2,2.4mmol·L-1)对L型钙离子通道的活动无明显影响;浓度达到4.8,9.6mmol·L-1时,L型钙离子通道平均开放时间由对照组的11.773±4.838ms分别减少到7.948±2.513ms和4.533±0.828ms(P<0.05),浓度进一步增加到19.2mmol·L-1时,通道平均开放时间降至3.042±0.792ms(P<0.05)。当葛根素达到一定浓度(4.8,9.6mmol·L-1)时,通道开放概率由对照组的0.0011±0.0001分别减小到0.00053±0.00018和0.00032±0.00013(P<0.05),随着浓度的进一步增加(19.2mmol·L-1),开放概率降至0.00021±0.00009(P<0.05)。总体而言,葛根素可以抑制单个大鼠海马CA1区锥体细胞L型钙离子通道活动,减少通道开放时间,降低通道开放概率。结论:葛根素可以抑制大鼠海马CA1区锥体细胞L型钙离子通道,减少通道开放时间,降低通道开放概率,并成浓度依赖性。提示临床上葛根素治疗缺血性中风可能与其抑制神经细胞L型钙离子通道的开放,防止钙超载有关。更多还原

【Abstract】 Objective:To observe the effect of Puerarin on L -type calcium channel in CA1 pyramidal neurons in hippocampus of adult rats after giving several concentrations. Methods: The pyramidal neurons in hippocampal CA1 region were dissociated acutely from SD adult rats by the enzymatical and automatical way. The cell suspension was then placed into a 35mm petri dish .After allowing the cell to settle , selecting the cell that accord with our experimental conditions. Then recording the ionic channel activity at the same holding voltage by the cell-attached of patch clamp techniques. Results: No significant effect were seen in L -type calcium channel in CA1 pyramidal neurons with the low concentrations of puerarin(1.2, 2.4mmol·L -1). At a given holding voltage ,significant change was observed in the open time of the L-type calcium channel after infusing Puerarin(4.8, 9.6, 19.2mmol·L -1 ). Open time was 11.773±4.838 ms for control , 7.948±2.513ms for concentration of 4.8mmol L -1( P<0.05,n=5 ), and 4.533 0.828ms( 9.6mmol L -1, P<0.05 vs control ) , then 3.042±0.792ms( 19.2mmol·L -1, P<0.05 vs control ). The open probability was 0.0011±0.0001 in control , decrease to 0.00053±0.00018( 4.8mmol·L -1,P<0.05 vs control ), and 0.00032±0.00013( 9.6mmol·L -1, P<0.05 vs control ), then went down 0.00021±0.00009( 19.2mmol·L -1, P<0.05vs control ). Conclution: Puerarin can inhibit L -type calcium in CA1 pyramidal neurons, decrease the open time , reduce the open probability. Which implies that Puerarin takes part in treatment of ischemia stoke in clinic partly due to the inhibition of L -type calcium channel in neuron.更多还原