糖尿病大鼠冠状动脉平滑肌细胞中大电导钙离子激活钾通道电流和钙离子浓度变化  

Changes of large conductance Ca^(2+)-activated K^+ channel current and cytosolic calcium concentrations in coronary artery smooth muscle cells of rats with diabetes

作　　者：吴莹[1] 王如兴[1] 郑杰[1] 李库林[1] 张常莹[1] 郭素峡[1] 刘晓宇[1] 李肖蓉[1] 

机构地区：[1]南京医科大学附属无锡市人民医院心脏病科,江苏省214023

出　　处：《江苏医药》2012年第2期128-130,共3页Jiangsu Medical Journal

基　　金：国家自然科学基金(81070157);江苏省自然科学基金(BK2011179);江苏省人事厅"六大人才高峰"第七批高层次项目(006)

摘　　要：目的探讨糖尿病大鼠冠状动脉平滑肌细胞中大电导钙离子激活钾通道(BK通道)电流及钙离子浓度的变化。方法 40只SD大鼠随机均分为正常对照组(A组)和糖尿病组(B组)。采用链脲霉素腹腔内注射建立糖尿病大鼠模型,酶消化法分离冠状动脉平滑肌细胞,全细胞膜片钳实验和荧光测定方法分别检测冠状动脉平滑肌细胞BK通道电流和钙离子浓度。结果与A组相比,当刺激电压大于60mV时,B组冠状动脉平滑肌细胞BK通道电流密度明显下降(P<0.05);A组冠状动脉平滑肌细胞内钙离子浓度明显低于B组[(103±23)nmol/L vs.(193±22)nmol/L](P<0.05)。结论冠状动脉平滑肌细胞中BK通道电流下降及细胞内钙离子浓度升高可能是糖尿病冠状动脉功能损伤的重要原因。Objective To investigate the changes of large conductance Ca^2＋-activated K^＋ channel（BK channel） current and cytosolic calcium concentrations in the coronary artery smooth muscle cells of rats with diabetes.Methods Forty SD rats were equally randomized into two groups of A（normal controls） and B（diabetic rats）.The streptozotocin-induced diabetic rat model was successfully established by intraperitoneal injection,and the coronary artery smooth muscle cells were isolated by enzyme digestion.BK channel currents and calcium concentrations were detected by whole-cell patch clamp technique and fluorescence assay,respectively.Results Compared with group A,the current density of BK channel in the coronary artery smooth muscle cells was significantly decreased in group B when test potential was more than 60 mV（P〈0.05）.The calcium concentration in group A was lower than that in group B [（103±23） nmol/L vs.（193±22） nmol/L]（P〈0.05）.ConclusionThe decrease of BK channel current and increase of cytosolic calcium concentration in the coronary artery smooth muscle cells of rats with diabetes may be the important causes for coronary dysfunction.

关 键 词：大电导钙离子激活钾通道 糖尿病 

分 类 号：R543[医药卫生—心血管疾病]