自主神经系统在心房钠尿肽分泌调节中的作用

发布时间：2018-03-10 20:05

本文选题：心房钠尿肽　切入点：自主神经系统　出处：《泰山医学院》2009年硕士论文　论文类型：学位论文

【摘要】： 目的心房钠尿肽(atrial natriuretic peptide,ANP)是参与血压和体液调节的内源性肽类激素,对机体的稳态起着重要作用。本研究以正常和甲状腺机能亢进(甲亢)性心肌肥大兔心房为研究对象,探讨自主神经系统对心房ANP分泌的调节作用,从而阐明心脏内分泌特性的新领域,为临床防治心脏疾病提供新的理论依据。方法实验选用体重约2 Kg的新西兰大耳白兔,采用离体搏动心房灌注模型和迷走神经—右心房模型进行实验。①离体搏动心房灌注模型实验:分对照组和甲亢性心肌肥大模型组。每天经家兔皮下注射0.5 mg/kg剂量L-thyroxin(T4)或vehicle制备甲亢性心肌肥大模型和对照组。通过心脏指数和心肌HE染色,评判甲亢性心肌肥大造模程度。用HEPES缓冲液灌注心房60 min稳定心房动力后,将3H-菊粉加到心房外液再稳定20 min,开始收集样品。灌流液每2 min收集一管,共42管。用乙酰胆碱(acetylcholine,ACh)和异丙肾上腺素(isproterenol,ISO)进行处理。观察ACh的单独效应时,前24管(48 min)为对照,后18管(36 min)注入ACh。观察ISO和ACh的联合作用时,前6管(12 min)为对照,从第7管开始加入ISO(36 min),到第25管时再加入ACh(36 min)。收集样品的同时观察心房每搏输出量和记录心房内压。②迷走神经—右心房模型实验:分离正常家兔的右侧迷走神经和右心房,置于麦氏浴器中,每2 min取出100μl迷走神经刺激前和后的心房周围的营养液,同时利用生理信号记录仪记录心率和右心房张力。收集样品结束后,利用放射免疫分析技术检测样品中ANP含量。结果①在正常生理情况下,经外源性途径给予ACh,降低心房每搏输出量和心房内压,可促进心房ANP的分泌。②在正常生理情况下,ISO增加心房每搏输出量和心房内压,可降低心房ANP的分泌。③在正常生理情况下,ISO对ACh调节心房ANP分泌有促进作用。④在甲亢性心肌肥大病理生理情况下,ACh促进心房ANP分泌的效应减弱。⑤在甲亢性心肌肥大病理生理情况下,ISO对ACh调节心房ANP分泌的促进效应减弱。⑥在正常生理情况下,刺激迷走神经,诱导内源性ACh生成,可导致心率降低、心房张力减小和心房ANP分泌水平升高的效应。结论在正常生理情况下,自主神经系统对心房ANP分泌起着调节作用,而此作用在甲亢性心肌肥大病理生理情况下发生改变。
[Abstract]:Objective atrial natriuretic peptide (ANP) is an endogenous peptide hormone involved in the regulation of blood pressure and body fluid, which plays an important role in homeostasis. To investigate the regulation of autonomic nervous system on atrial ANP secretion, and to elucidate the new field of cardiac endocrine characteristics, and to provide a new theoretical basis for clinical prevention and treatment of heart diseases. Methods New Zealand white rabbits weighing about 2 kg were used in the experiment. In vitro pulsatile atrial perfusion model and vagus nerve-right atrial model. 1 Pulsatile atrial perfusion model in vitro: divided into control group and hyperthyroidism myocardial hypertrophy model group. Subcutaneous injection of 0.5 mg/kg daily in rabbits. The hyperthyroidism model and control group were established by L-thyroxinine T _ 4) or vehicle. Cardiac index and myocardial HE staining were used to induce hyperthyroidism. To evaluate the degree of hyperthyroidism induced myocardial hypertrophy, after perfusing the atrium with HEPES buffer for 60 min to stabilize the atrial dynamics, 3H-inulin was added to the extracardial fluid for 20 minutes and then the samples were collected. The perfusion fluid was collected every 2 min. 42 tubes were treated with acetylcholine acetylcholine acetylcholine (ache) and isoprenolol ISO). The single effect of ACh was observed in the first 24 tubes for 48 min, the latter 18 tubes for 36 min), and the combined action of ISO and ACh was observed for 12 min. From tube 7 to tube 25, ACh(36 was added. The output of atrial beats was observed and the intraatrial pressure was recorded. 2 vagus nerve-right atrium model experiment: the right vagus nerve and right atrium were isolated from normal rabbits, the right vagus nerve and the right atrium were isolated from the normal rabbit, the right vagus nerve and the right atrium were isolated from the right vagus nerve and the right atrium. Placed in a McDonnell Bath, take out 100 渭 l nutrient fluid around the atrium before and after vagus nerve stimulation every 2 min, and record heart rate and right heart rate using physiological signal recorder. Atrial tension. After collecting samples, radioimmunoassay was used to detect the content of ANP in the samples. Results 1 under normal physiological conditions, ache was given through exogenous pathway to reduce atrial output and intraatrial pressure. It can promote atrial ANP secretion. 2. Under normal physiological conditions, it can increase atrial output and intraatrial pressure. Can reduce atrial ANP secretion. 3. In normal physiological conditions, ANP can promote ACh to regulate atrial ANP secretion. 4. Effect of ach on ANP secretion in hyperthyroidism myocardium is weakened in hyperthyroidism myocardium under pathophysiological conditions. Under the condition of macropathophysiology, the promoting effect of ACh on the regulation of atrial ANP secretion was weakened. 6 under normal physiological conditions, Stimulation of vagus nerve and induction of endogenous ACh may lead to the decrease of heart rate, the decrease of atrial tension and the increase of atrial ANP secretion. Conclusion under normal physiological conditions, autonomic nervous system plays an important role in regulating atrial ANP secretion, and this effect changes in hyperthyroidism myocardial hypertrophy.
【学位授予单位】：泰山医学院
【学位级别】：硕士
【学位授予年份】：2009
【分类号】：R33

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