镰刀菌毒素脱氧雪腐镰刀菌烯醇对心肌细胞Ca^(2+)通道的阻滞作用  

Blocking Effect of Deoxynivalenol(DON)on Calcium Channels in Cultured Cardiomyocytes of Rats

作　　者：彭双清[1] 杨进生[1] 

机构地区：[1]军事医学科学院毒物药物研究所,北京100850

出　　处：《中国预防医学杂志》2004年第4期241-243,共3页Chinese Preventive Medicine

基　　金：国家自然科学基金资助项目(30 340 0 0 4 )

摘　　要：目的　观察镰刀菌毒素单端孢霉烯族化合物脱氧雪腐镰刀菌烯醇 (DON)对培养心肌细胞Ca2 +通道单通道电活动的影响。方法　取新生 1～ 2日龄Wistar大鼠 ,分离心肌细胞 ,培养基为 80 %DMEM与 2 0 %小牛血清 ,于3 7℃ ,在含 5 %CO2 与 95 %空气的培养箱内进行培养 ,于培养 2 4～ 48h期间进行实验记录。采用贴附式膜片钳技术 ,记录心肌细胞B、L、T三型Ca2 +通道单通道电活动为加入毒素前对照 ,然后向培养基中加入 1mg·ml-1DON ,以观察DON对心肌细胞Ca2 +通道单通道电活动的影响。结果　DON浓度为 1mg·ml-1时 ,心肌细胞B ,L ,T三型Ca2 +通道均受到明显的阻滞。其阻滞作用表现在使B、L、T三型Ca2 +通道的开放时间分别缩短 47 3 % ,42 1%和 17 1% ,关闭时间分别延长 2 83 3 % ,92 8%和 40 7% ,使通道的开放概率分别下降 77 8% ,71 1%和 42 8%。而对流过B ,L ,T三型Ca2 +通道的Ba2 +流幅值均无明显影响。结论　DON能抑制大鼠培养心肌细胞的Ca2Objective To study the effect of deoxynivalenol(DON),a mycotoxin produced by Fusarium graminearum, on calcium channels in cultured cardiomyocytes of rats Methods Ventricular myocytes from neonatal Wistar rats were cultured,and the effects of DON on the single channel activities of B-type,L-type and T-type of Ca 2+ channels were studied by using cell-attached clamp technique after 24-48 hours of culture The channel opening of L-and T-type calcium were evoked by a depolarizing test pulse from -50 mV to+10 mV and from-70 mV to-10 mV respectively While,the B-type calcium channel was recorded at -60 mV without depolarizing test pulse The single channel recordings were made before and after addition of DON in the bath solution at concentration of 1mg·ml -1 Results DON at dose of 1mg·ml -1 significantly inhibited the activities of the three types of Ca 2+ channels The open time of B-type,L-type and T-type of Ca 2+ channels was shortened by 47 3%,42 1%and 17 1% respectively The open-state probability of B-type,L-type and T-type Ca 2+ channels was decreased by 77 8%,71 1% and 42 8% respectively,whereas there were no significant variations in the amplitude of current flowing through the Ca 2+ channels Conclusions DON inhibit the activities of calcium channels of cultured cardiomyocytes,suggestting the cardiotoxicity of DON may be due to block of calcium channels

关 键 词：镰刀菌毒素 脱氧雪腐镰刀菌烯醇 心肌细胞 CA^2+通道 阻滞作用 

分 类 号：R541[医药卫生—心血管疾病]