慢性间歇性低压低氧对清醒大鼠心率变异性的影响

发布时间：2018-05-04 09:50

本文选题：慢性间歇性低压低氧 + 急性低氧　；参考：《河北医科大学》2011年硕士论文

【摘要】：目的:近年来,慢性间歇性低压低氧(chronic intermittent hypobaric hypoxia, CIHH)对心脏的保护作用及其机制的研究越来越引起人们的关注,已成为临床医学、航天医学和高原医学等领域的研究热点之一。大量研究表明,CIHH对成年大鼠具有明显的心脏保护作用,显著提高心肌抗缺血/再灌注或缺氧/复氧损伤能力,减轻缺血/再灌注后心脏舒缩功能的降低,预防缺血/再灌注心律失常的发生。其作用机制可能与氧的运输、能量代谢、神经体液调节、抗氧化酶、应激蛋白、腺苷系统、ATP敏感钾通道、线粒体及其钙调控、一氧化氮和蛋白激酶等多方面因素有关。心脏自主神经调控在维持心脏正常生理功能中发挥重要作用,并参与多种心脏疾患的病理过程。心脏的健康状况及自主神经调节能力可采用心率变异性进行评价。有关CIHH对心率变异性的影响,或CIHH心脏保护中是否有自主神经调控参与,迄今尚未明w１疚闹荚谕ü２饧际豕鄄霤IHH处理对清醒大鼠心率变异性(HRV)的影响,探讨CIHH对心脏自主神经调节的影响或CIHH心脏保护作用的心脏自主神经调控机制。方法:雄性成年Spraque-Dawly大鼠随机分为对照组(CON, n=6),间歇性低压低氧处理组(CIHH, n=6)。CIHH组大鼠置于低压氧舱,给予42天模拟海拔5000米的低压低氧处理,每天6小时,其余时间处于常氧环境。CON组大鼠持续处于常氧环境。每周定时记录动物体重及一般状况。应用美国Data Sciences International(DSI)公司生产的生理参数遥测系统监测清醒大鼠标准肢体Ⅱ导联心电图,通常于每天上舱前、中、后持续记录实验数据,通过分析软件测定HRV,进行频谱分析,指标包括总功率(TP)、极低频成分(VLF)、低频成分(LF)、高频成分(HF)、低频/高频比值(LF/HF)及心率(HR)。所有数据均以均数±标准差(mean±SD)表示,组间比较采用t检验,P0.05认为具有显著性差异,P0.01有极显著性差异。结果:(1)大鼠的体重随年龄增长而增加,CIHH与CON大鼠体重无明显差异(P0.05)。 (2)在常氧环境中,CIHH与CON大鼠的TP与VLF值无明显差异(P0.05)。CIHH大鼠在模拟低压低氧环境中,从第4周开始,其TP及VLF值明显降低(P0.05);在急性低氧条件下,CON大鼠的TP及VLF值明显减小(P0.05),而CIHH大鼠的TP及VLF值无明显改变(P0.05)。 (3)在常氧环境中,CIHH与CON大鼠的LF及LF/HF值无明显差异(P0.05)。CIHH大鼠在模拟高原低压处理过程中,第1周其LF及LF/HF值明显增高(P0.05);2周后逐渐恢复正常水平(P0.05)。CIHH大鼠的HF值,无论在模拟高原环境或常氧环境中,与CON大鼠相比均无明显差异(P0.05)。急性低氧条件下,CON大鼠LF值无明显变化,而HF值明显下降(P0.05),LF/HF值明显增高(P0.05);CIHH大鼠的LF值、HF值和LF/HF值均无显著变化(P0.05)。 (4)在实验过程常氧环境下,CON大鼠心率持续降低,于第4周时明显低于其基础值及CIHH组大鼠低压低氧状态下心率(P0.05);于第6周时明显低于CIHH大鼠心率(P0.05)。CIHH组大鼠无论在常氧环境还是模拟低压低氧环境下,其心率均无明显变化(P0.05)。急性低氧条件下,大鼠心率明显增加,而CON大鼠心率增加(34%)明显超过CIHH大鼠(10%)。结论:CIHH处理对大鼠基础心率变异性无明显影响,但可显著降低急性低氧对心率及其变异性的影响。其作用可能与CIHH过程中交感神经调控能力的增强,以及对抗急性低氧时心迷走张力降低有关。
[Abstract]:Objective: in recent years, the study of the protective effect of chronic intermittent hypobaric hypoxia (CIHH) on the heart and its mechanism has attracted more and more attention. It has become one of the hot topics in the fields of clinical medicine, space medicine and high altitude medicine. A large number of studies have shown that CIHH has obvious effect on adult rats. Cardiac protective effect significantly improves the ability of myocardial ischemia / reperfusion or hypoxia / reoxygenation, reduces cardiac contractility after ischemia / reperfusion and prevents ischemic / reperfusion arrhythmia. Its mechanism may be associated with oxygen transport, energy metabolism, neurohumoral regulation, antioxidant enzyme, stress protein, adenosine system, ATP sensitivity Potassium channels, mitochondria and their calcium regulation are related to many factors such as nitric oxide and protein kinase. Cardiac autonomic nerve regulation plays an important role in maintaining the normal physiological function of the heart, and participates in the pathological process of various heart diseases. Heart health status and autonomic nerve regulating ability can be evaluated by heart rate variability. The effect of CIHH on heart rate variability, or whether CIHH is involved in autonomic nervous regulation in heart protection, has not yet been identified as w? 1? Guilt pods u? 2, the effect of IHH treatment on heart rate variability (HRV) in conscious rats, the effect of CIHH on cardiac autonomic nerve regulation or the cardiac autonomic nervous regulation of CIHH cardiac protection System.
Methods: male adult Spraque-Dawly rats were randomly divided into the control group (CON, n=6), the intermittent hypobaric hypoxia treatment group (CIHH, n=6) group.CIHH rats were placed in the hypobaric oxygen chamber for 42 days at an altitude of 5000 meters at low pressure and hypoxia treatment, 6 hours a day, and the rest of the rest time was in the normal oxygen environment and kept in the normal oxygen environment. The weight of the object and the general condition.
The physiological parameter telemetry system produced by Data Sciences International (DSI) is used to monitor the standard limb II lead electrocardiogram of sober rats. The experimental data are recorded continuously in front of the cabin, in the middle, and after the analysis software, and the spectrum analysis is carried out by the analysis software, including the total power (TP), the extremely low frequency component (VLF), the low frequency component (LF). High frequency components (HF), low frequency / high frequency ratio (LF/HF) and heart rate (HR).
All data were expressed by mean + standard deviation (mean + SD). T test was used in comparison between groups. P0.05 thought there was significant difference, P0.01 had very significant difference.
Results: (1) the weight of rats increased with age, and there was no significant difference in body weight between CIHH and CON rats (P0.05).
(2) in the normoxic environment, the TP and VLF values of CIHH and CON rats were not significantly different (P0.05).CIHH rats in the simulated hypobaric hypoxia environment, the values of TP and VLF decreased significantly (P0.05) from the beginning of the fourth week, and the TP and VLF values of CON rats decreased significantly under the acute hypoxia conditions.
(3) in the normal oxygen environment, the LF and LF/HF values of CIHH and CON rats were not significantly different (P0.05).CIHH rats in the simulated plateau low pressure treatment, the value of LF and LF/HF increased significantly at first weeks (P0.05), and the HF values of normal level (P0.05).CIHH rats were gradually restored after 2 weeks. There was no significant difference (P0.05). In acute hypoxia, the LF value of CON rats was not significantly changed, while the HF value decreased significantly (P0.05), and the LF/HF value increased significantly (P0.05). There was no significant change in LF value, HF value and LF/HF value in CIHH rats (P0.05).
(4) in the normal oxygen environment, the heart rate of CON rats decreased continuously. At fourth weeks, the heart rate was significantly lower than that in the basal and CIHH rats (P0.05). At sixth weeks, the heart rate of group.CIHH rats was significantly lower than that of the CIHH rats (P0.05) in the normal oxygen environment and the simulated low pressure hypoxia environment, the heart rate was not significantly changed (P0.0 5) under acute hypoxic condition, the heart rate of rats increased significantly, while the heart rate of CON rats increased (34%), which was significantly higher than that of CIHH rats (10%).
Conclusion: CIHH treatment has no significant effect on rat basal heart rate variability, but it can significantly reduce the effect of acute hypoxia on heart rate and its variability, which may be related to the enhancement of the sympathetic nervous regulation in the CIHH process and the decrease of cardiac vagus tension in acute hypoxia.

【学位授予单位】：河北医科大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：R363

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