摘要
目的探索猪的冠状动脉中,钙激活钾通道(Calcium-activated potassium channels,K_Ca)在内皮源性超极化因子(Endothelium-Derived Hyperpolarizing Factor,EDHF)介导的血管舒张中的作用。方法 K_Ca通常分为三类:大电导K_Ca(Large-Conductance K_Ca,BK_Ca),中电导K_Ca(Intermediate-Conductance K_Ca,IK_Ca)和小电导K_Ca(Small-Conductance K_Ca,SK_Ca),因此根据加入K_Ca阻滞剂的不同,将血管环分为对照组(不加入K_Ca阻滞剂),Charybodotoxin(BK_Ca和IK_Ca通道阻断剂)组,Apamin(SK_Ca通道阻断剂)组,Charybodotoxin+Apamin组,Iberiotoxin(BK_Ca通道阻断剂)组,每组血管环n=6。采用器官槽法,所有血管环平衡1h后,对照组加入7umol/L环加氧酶阻滞剂吲哚美辛(Indomethacin,Indo)和300 umol/L一氧化氮合酶阻滞剂N-硝基-L-精氨酸(N-nitro-L-arginine,L-NNA),实验组在加入Indo和L-NNA的基础上分别或联合应用BK_Ca、IK_Ca和SK_Ca的阻断剂,水浴30min后,记录由前列腺素F2α(Prostaglandin F2α,U46619)及缓激肽(Bradykinin,BK)引起的血管收缩和舒张反应。结果 Charybodotoxin组,Charybodotoxin+Apamin组和Iberiotoxin组中EDHF介导的内皮依赖性血管最大舒张百分比与对照组相比显著下降,且Charybodotoxin组的最大舒张百分比较Charybodotoxin+Apamin组更低,但Apamin组血管环最大舒张百分比与对照组相比无统计学意义。结论研究证明BK_Ca和SK_Ca通道均在EDHF介导的舒张功能中发挥一定作用,且以协同的方式作用于血管,IK_Ca通道也可能发挥了一定的作用。
Objective The present study was designed to explore the role of Kca, in the EDHF-mediated endothelium-dependent vasodilatation. Methods Generally Kca, can be divided into three types： Large-Conductance Kca, Intermediate-Conductance Kca, and Small-Conductance Kca. According to different Kc, blockers used in different groups, the rings were divided into the following groups： control group, Charybodotoxin （a blocker of BKca and IKca channels） group, Apamin （a specific blocker of SKca, channels） group, Charybodotoxin＋Apamin group, lberiotoxin （a specific blocker of BKca channels） group. Rings from porcine coronary arteries were studied in the organ chamber, after equilibration for I hour, the control group rings were incubated with 7umol/L lndomethacin and 300 umol/L L-NNA. the other groups were incubated with 7umol/L Indomethacin, 300 umol/L L-NNA and different calcium-activated potassium channel blockers. Then Pre-contraction tone induced by prostaglandin F2c~ U466l 9 and endothelium-dependent relaxation tone induced by bradykinin was measured in the presence of indomethacin and L-NNA with/without different calcium-activated potassium channel blockers. Results Compared with the control group, EDHF-mediated endothelium-dependent relaxation induced by bradykinin was significantly decreased in the Charybodotoxin group, Charybodotoxin＋Apamin group and lberiotoxin group, while the relaxation of Apamin group was not statistically significant in comparision with the control group. Conclusion Studies have shown that both BKca, and SKca, channels play a role in EDHF-mediated relaxation, and act in a coordinated manner on blood vessels, in addition, lKca channel is also likely to play a role.
出处
《中国分子心脏病学杂志》
CAS
2014年第1期834-838,共5页
Molecular Cardiology of China
基金
国家自然科学基金资助项目(30972866)
北京市自然科学基金资助项目(7102131)
关键词
血管环
内皮源性超极化因子
钙激活钾通道
Vascular Rings
Endothelium-derived Hyperpolarizing Factor
Calcium-activated Potassium Channels
