有氧运动对大鼠脑动脉平滑肌细胞BKca通道生物物理特性的影响

发布时间：2018-04-08 23:15

本文选题：有氧运动　切入点：BKca通道　出处：《北京体育大学》2012年硕士论文

【摘要】：研究目的：观察有氧运动对大鼠脑动脉平滑肌细胞BKCa通道生物物理特性的影响。研究方法：8周龄雄性Wistar大鼠30只,随机分为三组,安静对照组(SED),高频运动组(EX-5d／w)和低频运动组(EX-3d／w)各10只。运动组进行12周跑台运动(0°slope,20m、min,50-55％VO2max,60min/day),其中EX-3d／w组每周运动3次,EX-5d／w组每周运动5次。12周后,将大鼠麻醉,断头处死,迅速打开颅腔取脑。小心取出基底动脉及Willis环,剥除周围结缔组织,经酶法消化后得到单个脑动脉平滑肌细胞。膜片钳实验采用单通道内面向外模式记录,观察各组大鼠脑动脉BKCa通道的生物物理特性。研究结果：(1)BKCa通道鉴定：本实验单通道电导为210.5±10,3pS(R2=0.996,n=8)；记录电流反转电位接近OmV,无整流现象,均符合BKCa单通道特征。(2)有氧运动使BKCa通道活性提高：膜电位+40mV,[Ca2+]i为1μM时,SED、EX一3d/w和EX-5d／w各组BKCa通道平均开放概率分别为0.28±0.015,0.47±0.02,0.78±0.067。(3)有氧运动使BKCa通道电压依赖性增强：[Ca2+]i为1μM时,SED. EX-3d/w. EX-5d/w三组(Normal ized Npo)-V曲线依次左移,三组V1／2分别为44.52mV,37.08mV,26.55mV.(4)有氧运动使BKCa通道钙敏感性增强：膜电位+40mV下,SED、EX-3d/w. EX-5d/w三组(Normalized NPo)-Log[Ca2+](?)曲线依次左移,Kd值分别为2.801±0.086μM,1.39±0.079μM,0.35±0.087μM。(5)运动组大鼠BKCa通道平均开放时间(To)增大;平均关闭时间(Tc)减小,提示有氧运动使通道更易开放且更难关闭。结论：长期规律性有氧运动能改变大鼠脑动脉平滑肌细胞BKCa通道的门控特性,使其活性增强,这可能是运动改善脑血管舒缩功能,增强脑动脉供血.的重要机制之一；有氧运动改善BKCa通道活性的效果可能呈运动量依赖性。
[Abstract]:Aim: to observe the effects of aerobic exercise on the biophysical properties of BKCa channels in rat cerebral artery smooth muscle cells.Methods Thirty eight week-old male Wistar rats were randomly divided into three groups: the quiet control group, the high frequency exercise group (EX-5d / w) and the low-frequency exercise group (EX-3d / w).The rats in the exercise group were treated with 0 掳slopetrope (20 掳slopetrol) for 12 weeks. The rats in the EX-3d/w group were treated with EX-5 d / w 3 times a week for 5 times a week. The rats were anesthetized and killed by severed, and the brain was quickly opened to the cranial cavity for brain extraction. The rats in the EX-3d/w group were treated with EX-5d / w exercise three times a week. The rats were anesthetized, killed and quickly opened to the skull for brain extraction.The basilar artery and Willis ring were carefully removed and the connective tissue around them was stripped. The smooth muscle cells of single cerebral artery were obtained by enzymatic digestion.Single channel inward and outward mode was used to observe the biophysical characteristics of BKCa channel in the cerebral artery of rats in each group.The results showed that the single channel conductance of this experiment was 210.5 卤10 ~ 3pSN ~ (2) 0.996N ~ (-1) N ~ (8), the current reversal potential was close to OmV, and there was no rectifying phenomenon.EX-3 d / w.The normal ized Npo)-V curve of the three groups of EX-5d/w shifted to the left in turn. The V1 / 2 of the three groups was 44.52 MV, 37.08 MV, 26.55 MV. 4) aerobic exercise enhanced the calcium sensitivity of the BKCa channel: SEDX EX-3 d / w at the membrane potential 40mV.EX-5d/w NPo)-Log [Ca2]The mean opening time of BKCa channel increased and the mean closing time decreased in the exercise group, indicating that aerobic exercise could make the channel more open and difficult to close. The curve shifted to the left and the KD value was 2.801 卤0.086 渭 MU 1.39 卤0.079 渭 MU 0.35 卤0.087 渭 M.M.) in the exercise group, the mean opening time of the BKCa channel increased and the mean closing time decreased, indicating that aerobic exercise made the channel easier to open and harder to close.Conclusion: Long-term regular aerobic exercise can change the gated characteristics of BKCa channel in rat cerebral artery smooth muscle cells and increase its activity, which may be due to the improvement of cerebral vasomotor function and the enhancement of cerebral artery blood supply by exercise.The effect of aerobic exercise on improving BKCa channel activity may be in a dose-dependent manner.
【学位授予单位】：北京体育大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：G804.2

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