缬沙坦调控自发性高血压大鼠血压昼夜节律的生物钟机制研究

发布时间：2018-04-15 11:33

本文选题：缬沙坦 + 自发性高血压大鼠　；参考：《皖南医学院》2017年硕士论文

【摘要】：昼夜节律是生物界常见的生物节律之一,人类许多生理生化功能和行为均呈现出昼夜节律变化。高血压是最常见的心血管疾病之一,现如今,血压昼夜节律模式已列为高血压诊断和评估心血管事件的参考标准之一。血管紧张素Ⅱ(angiotensinⅡ,AngⅡ)与高血压发生密切相关,并参与血压昼夜节律的调节,缬沙坦是AngⅡ受体拮抗剂,能选择性阻断AT1受体。本课题组前期临床研究显示昼夜不同时间用药,缬沙坦对非杓型高血压患者的血压昼夜节律有显著影响,休息期用药,可使高血压患者非杓型血压节律明显改善,但有关其调控血压昼夜节律的生物钟机制尚不清楚。本实验以生物钟系统昼夜节律调控的核心机制为理论指导,探讨缬沙坦对异常血压昼夜节律的干预作用以及对生物钟基因Per1、Per2表达节律的影响,从整体水平阐明生物钟基因Per1、Per2参与缬沙坦调控血压昼夜节律的机制。本课题研究获得的信息将为高血压的时辰治疗提供理论基础以及为寻找更理想的降压药物提供新思路。目的:观察缬沙坦对自发性高血压大鼠血压昼夜节律的调控作用以及不同时间点给药对血压水平、血压昼夜节律的影响,并探讨其生物钟机制。方法:10周龄雄性自发性高血压大鼠(SHR)和10周龄雄性Wistar-Kyoto大鼠(WKY)置于时间生物学实验室内适应性喂养2周,参照WKY大鼠血压昼夜节律模式作为正常对照组,确定SHR大鼠异常血压昼夜节律模式。将其随机分为三组:SHR模型组、缬沙坦08:00组、缬沙坦20:00组。灌胃给予缬沙坦30mg/kg,连续给药6周。采用尾袖法,于给药前、给药后每2周分别测量各组大鼠连续24h尾动脉血压。给药6周后,各组动物依次分别在24h内7个时间点(CT0,CT4,CT8,CT12,CT16,CT20,CT24)进行采集样品。采用 ELISA法检测血浆AngⅡ、ACE、REN、ALD含量,观察各项指标24h动态变化,分析昼夜节律;HE染色和Masson染色观察心脏和主动脉靶器官病理损伤程度。Real-time PCR法检测大鼠下丘脑、主动脉生物钟基因Per1、Per2 mRNA表达水平,观察24h动态变化,分析昼夜节律;Western blot法检测主动脉生物钟蛋白PER1、PER2蛋白表达水平,观察24h动态变化,分析昼夜节律;结果:(1)在给药期间,与模型组相比,缬沙坦08:00组的收缩压、舒张压和平均动脉压均降低(P0.01),血压杓型值升高(P0.01),血压昼夜节律参数中值降低,振幅升高,峰值相位前移,其异常血压昼夜节律得到明显改善(P0.01);缬沙坦20:00组的收缩压、舒张压和平均动脉压均降低(P0.01),但血压杓型值并未明显升高。(2)给药6周后,与模型组相比,缬沙坦08:00组的血浆AngⅡ休息期水平升高,活动期水平降低,振幅升高(P0.01);肾素整体水平降低,血管紧张素转化酶和醛固酮整体水平升高(P0.01),血浆中RAAS系统昼夜节律发生改变。(3)给药6周后,与模型组相比,缬沙坦08:00组的脏器系数降低,心脏和主动脉靶器官的病理损伤明显得到缓解;缬沙坦20:00组的靶器官病理损伤缓解程度不及缬沙坦08:00组。(4)给药6周后,与模型组相比,缬沙坦08:00组的下丘脑组织Per1 mRNA活动期表达升高,Per2 mRNA休息期表达升高(P0.05);(5)给药6周后,与模型组相比,缬沙坦08:00组的主动脉组织中Per1 mRNA和Per2 mRNA整体表达降低,中值和振幅降低(P0.01);主动脉组织中PER1蛋白活动期表达升高,PER2蛋白整体表达升高(P0.01);生物钟基因Per1、Per2 mRNA和蛋白表达昼夜节律发生改变。结论:相对于活动期用药,缬沙坦休息期用药不仅能有效降低血压,保护靶器官心脏和主动脉病理损伤,还能明显改善自发性高血压大鼠的异常血压昼夜节律,使其逆转为杓型血压昼夜节律,其机制可能与影响血浆RAAS系统的昼夜节律性,进而改变下丘脑和主动脉生物钟基因Per1、Per2 mRNA与蛋白表达的昼夜节律性有关。
[Abstract]:Circadian rhythm is one of the common biological rhythms in biology, many human physiological and biochemical function and behavior showed circadian rhythm changes. Hypertension is one of the most common cardiovascular disease nowadays, has been listed as one of the circadian blood pressure pattern reference standard for hypertension diagnosis and assessment of cardiovascular events. Angiotensin II (angiotensin II. Ang II) is closely related to hypertension, and involved in the regulation of circadian rhythm of blood pressure. Valsartan is Ang receptor antagonist, selective blockade of AT1 receptor. Our previous clinical studies have shown that day at the same time medication, have a significant effect of valsartan on circadian rhythm of blood pressure in patients with non dipper hypertension, rest period medication, can the hypertensive patients with non dipper rhythm of blood pressure significantly improved, but the biological clock mechanism related to its regulation of circadian rhythm of blood pressure is not clear. In this experiment, the circadian clock systems The core mechanism of rhythm regulation theory, the effects of valsartan on abnormal circadian rhythm of blood pressure and the circadian clock gene Per1, Per2 expression of rhythm, from the overall level to clarify the biological clock gene Per1, Per2 participates in the regulation mechanism of valsartan on the circadian rhythm of blood pressure. Research on this topic will get information for the treatment of hypertension. To provide a theoretical basis and provide new ideas for more ideal antihypertensive drugs. Objective: To observe the effect of valsartan on regulation of circadian rhythm of blood pressure in spontaneously hypertensive rats and administration in different time on blood pressure level, affect the circadian rhythm of blood pressure, and to explore the biological clock mechanism. Methods: 10 week old male spontaneously hypertensive rats (SHR) and 10 week old male Wistar-Kyoto rats (WKY) in 2 weeks time in the biology laboratory reference adaptive feeding, circadian rhythm of blood pressure model WKY rats As the normal control group, SHR rats abnormal circadian rhythm of blood pressure. They were randomly divided into three groups: SHR model group, valsartan group 08:00, valsartan group. 20:00 intragastric administration of 30mg/kg valsartan administered continuously for 6 weeks. By using the tail cuff method, prior to drug administration, every 2 weeks after treatment respectively. Continuous 24h measuring the blood pressure of tail artery volume of rats. After 6 weeks of treatment, each animal respectively in 24h 7 time points (CT0, CT4, CT8, CT12, CT16, CT20, CT24) were collected. Plasma samples were detected with ELISA Ang II, ACE, REN, ALD in the observation 24h index analysis of dynamic change of circadian rhythm; HE staining and Masson staining were used to observe the heart and aorta were the target organs damage degree of.Real-time PCR was detected in rat hypothalamus, aortic clock gene Per1, Per2 expression level of mRNA, the dynamic changes of 24h, analysis of circadian clock protein PER; detection of aortic Western blot method 1, the expression level of PER2 protein, the dynamic changes of 24h, analysis of circadian rhythm; results: (1) during the period of delivery, compared with the model group, valsartan group 08:00 systolic pressure, diastolic pressure and mean arterial pressure (P0.01) decreased, increased blood pressure dipper value (P0.01), blood pressure circadian rhythm parameters the median decreased and the amplitude increased peak phase forward, the abnormal circadian rhythm of blood pressure was significantly improved (P0.01); valsartan group 20:00 systolic pressure, diastolic pressure and mean arterial pressure (P0.01) decreased, but the blood pressure did not increase obviously. The dipper value (2) after 6 weeks of treatment, compared with the model group. Plasma Ang II valsartan group 08:00 resting levels, the level of activity decreased and the amplitude increased (P0.01); to reduce the overall level of renin, angiotensin converting enzyme and increase the overall level of aldosterone (P0.01), change the RAAS system. The circadian rhythm of plasma (3) after 6 weeks of treatment, compared with model group valerian. Reduce the organ coefficient of 08:00 group candesartan in heart and aorta, the pathological damage of target organs has been alleviated; target organ damage relieve pathological group valsartan 20:00 less 08:00 valsartan group. (4) after 6 weeks of treatment, compared with model group, valsartan group 08:00 group Per1 active mRNA fabric hypothalamic expression increased, Per2 mRNA expression increased rest period (P0.05); (5) after 6 weeks of treatment, compared with model group, valsartan group 08:00 in aortic tissue of Per1 mRNA and Per2 mRNA expression decreased, and the median amplitude decreased (P0.01); PER1 protein activity in aorta tissue expression increased, PER2 protein expression increased overall (P0.01); clock gene Per1, Per2 mRNA and protein expression of circadian rhythm changes. Conclusion: compared with the active drug, valsartan medication rest period not only can effectively reduce blood pressure, protect the target organs of the heart and aorta pathological damage, but also Improve abnormal circadian rhythm of blood pressure in spontaneously hypertensive rats, the reversal of circadian rhythm of blood pressure, and its mechanism may be related to circadian rhythm of plasma RAAS system, and then change the hypothalamus and aortic clock gene Per1, circadian rhythm of the expression of mRNA and Per2 protein.

【学位授予单位】：皖南医学院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R544.1

【参考文献】