本文選題：下丘腦后核(PH) + 心血管調(diào)控�。� 參考：《南京大學》2016年博士論文

【摘要】：促腎上腺皮質(zhì)激素釋放因子(corticotrophin releasing factor, CRF) 和 orexin是中樞神經(jīng)系統(tǒng)中兩類重要的神經(jīng)肽,在機體的許多生理功能調(diào)節(jié),如心血管活動調(diào)控中發(fā)揮著關鍵作用。在下丘腦這一心血管和自主性活動調(diào)控高級中樞中,不僅分布著能夠合成CRF或orexin的神經(jīng)元,而且有CRP受體和orexin受體的大量表達。下丘腦后核(The posterior hypothalamic nucleus, PH)是下丘腦中參與心血管調(diào)控的重要結(jié)構(gòu)之一。電刺激或化學刺激大鼠PH顯著升高心率、血壓和交感神經(jīng)活動；且慢性深部腦刺激慢性叢集性頭痛(一種血管性頭痛)患者PH伴隨著心血管系統(tǒng)交感興奮性驅(qū)動增強。因此,本論文旨在研究PH在中樞CRF能神經(jīng)系統(tǒng)心血管活動調(diào)控中的作用以及源自PH的orexin能神經(jīng)系統(tǒng)的心血管調(diào)控功能,從而有助于理解中樞CRF能和orexin能兩大神經(jīng)肽系統(tǒng)在機體心血管調(diào)控中的作用及機制。具體研究結(jié)果如下：一、CRF通過興奮PH神經(jīng)元產(chǎn)生心動過速反應CRF是一種與應激密切相關的肽類激素,在心血管活動調(diào)控中發(fā)揮關鍵作用。應用實時定量RT-PCR、免疫熒光組織化學、在體心血管活動記錄,并結(jié)合離體、在體電生理學記錄技術,我們研究了CRY對PH這一應激相關心血管活動調(diào)控中樞中神經(jīng)元的作用及其受體機制,特別是PH在CRF的中樞心血管調(diào)控功能中的作用。我們的研究發(fā)現(xiàn),大鼠PH神經(jīng)元上有CRF 1型受體(CRFR1)和CRF 2型受體(CRFR2)的共表達。離體腦片全細胞膜片鉗記錄表明,CRF能夠通過CRFR1 和 CRFR2的共同介導直接興奮PH神經(jīng)元。在體研究表明PH中微量注射CRF可濃度依賴性地增加心率,但對血壓和腎交感神經(jīng)活動(sympathetic nerve activity, RSI JA)沒有影響。CRFR1 和 CRFR2共同介導了這一CRF誘導的心動過速反應。進一步地,雙側(cè)迷走神經(jīng)切斷不能阻斷CRF經(jīng)PH誘導的心動過速,但靜脈注射腎上腺素p受體阻斷劑普洛萘爾可以完全阻斷這一CRF誘導的心動過速反應。此外,PH中微量注射CRF可以引起喙端腹外側(cè)延髓rostral ventrolateral medulla, RVLM)神經(jīng)元和喙端腹內(nèi)側(cè)延髓(rostralventromedial medulla, RVMM)神經(jīng)元放電頻率的變化,且這一變化以興奮性反應為主。但PH中微量注射CRF對迷走神經(jīng)運動背核(dorsal motor nucleus of the vagus nerve, DMNV)神經(jīng)元的放電活動沒有影響。這一結(jié)果表明,PH是中樞CRF能神經(jīng)系統(tǒng)調(diào)節(jié)心率的重要靶區(qū)之一；PH-RVLM/RVMM-心交感神經(jīng)通路,而非PH-DMNV-迷走神經(jīng)通路,參與介導了中樞CRF的心動過速效應。二、PH orexin能神經(jīng)元對心血管活動的調(diào)控及其機制除下丘腦外側(cè)區(qū)和穹窿周區(qū)之外,PH也是中樞orexin能神經(jīng)系統(tǒng)的重要起源之一。作為全腦功能調(diào)節(jié)者,中樞orexin能神經(jīng)系統(tǒng)不僅參與了睡眠覺醒、能量平衡、神經(jīng)內(nèi)分泌、獎賞、情緒和軀體運動調(diào)控,而且在機體心血管活動調(diào)節(jié)中發(fā)揮重要作用。由于PH亦是心血管活動調(diào)節(jié)的一個重要中樞,我們在本項目中深入研究了PH中orexin能神經(jīng)元的中樞心血管活動調(diào)控作用,及其神經(jīng)環(huán)路和受體、離子機制。我們的研究結(jié)果表明,第四腦室內(nèi)微量注射orexin1型受體(OX1R)阻斷劑(SB334867)和 orexin 2型受體(OX2R)阻斷劑(TCSOX2 29)可以顯著降低由bicuculline (GABAA受體阻斷劑)去抑制PH神經(jīng)元所誘發(fā)的動脈血壓升高、心動過速和腎交感神經(jīng)興奮性反應,提示PH中的orexin能神經(jīng)元參與了PH的心血管活動調(diào)控。順行示蹤和免疫熒光組織化學實驗表明,PH 中 orexin能神經(jīng)元有向腦干心血管活動調(diào)控中樞RVMM的中等密度神經(jīng)纖維投射和向RVLM的極少量投射。RVMM中微量注射SB334867或者TCS OX2 29均可顯著減弱去抑制PH誘導的升壓、心動過速和腎交感神經(jīng)興奮性反應。但RVLM中微量注射SB334867或者TCS oX2 29則無此阻斷效應。離體腦片全細胞膜片鉗記錄表明,orexin受體兩種亞型OX1R和OX2R及與它們耦聯(lián)的內(nèi)向整流K~+離子通道、Na~+-Ca~(2+)交換體和非選擇性陽離子通道共同介導了orexin 對 RVMM神經(jīng)元的興奮性效應。這一研究結(jié)果表明,PH中orexin能神經(jīng)元在中樞心血管活動調(diào)控中發(fā)揮了重要作用,而PH中orexin能神經(jīng)元向RVMM而非RVLM的神經(jīng)投射可能介導了PH的心血管調(diào)控作用。
[Abstract]:Adrenocorticotropic hormone releasing factor (corticotrophin releasing factor, CRF) and orexin are two important neuropeptides in the central nervous system, which play a key role in the regulation of many physiological functions, such as cardiovascular activities. In the hypothalamus, this cardiovascular and autonomic activity regulation is not only distributed in the advanced center. Neurons that can synthesize CRF or orexin and have a large number of CRP receptors and orexin receptors. The posterior nucleus of the hypothalamus (The posterior hypothalamic nucleus, PH) is one of the important structures involved in cardiovascular regulation in the hypothalamus. Electrical stimulation or chemical stimulation of rats PH significantly increases heart rate, blood pressure and sympathetic nerve activity; and chronic deep part PH, which stimulates chronic cluster headache (a vascular headache), is accompanied by a sympathetic stimulation of the cardiovascular system. Therefore, this paper aims to study the role of PH in the regulation of cardiovascular activities in the central CRF nervous system and the cardiac and vascular regulation of the orexin energy system derived from PH, thus helping to understand the central CRF energy. The role and mechanism of the two major neuropeptide systems of orexin in cardiovascular regulation. The results are as follows: 1, CRF is a peptide hormone closely related to stress, which is closely related to stress, and plays a key role in the regulation of cardiovascular activities. The application of real-time quantitative RT-PCR and immunofluorescence tissue is used in the regulation of CRF. Chemistry, in vivo cardiovascular activity records, and in vitro, in vivo electrophysiological recording techniques, we studied the role of CRY on neurons in the regulation of cardiovascular activity in the stress related PH and its receptor mechanism, especially the role of PH in the central cardiovascular regulation of CRF. Our study found that there are CRF in rat PH neurons. The co expression of type 1 receptor (CRFR1) and CRF type 2 receptor (CRFR2). Whole cell patch clamp recording in isolated brain shows that CRF can directly excitate PH neurons through the common mediating of CRFR1 and CRFR2. In vivo studies have shown that microinjection CRF in PH can increase heart rate in a concentration dependent manner, but for blood pressure and renal sympathetic activity (sympathetic nerve activi) Ty, RSI JA) did not affect both.CRFR1 and CRFR2 to mediate this CRF induced tachycardia reaction. Further, bilateral vagotomy does not block the CRF via PH induced tachycardia, but intravenous adrenaline blocker pralanyl can completely block this CRF induced tachycardia. Furthermore, PH is a trace of the tachycardia. Injection of CRF can cause the changes in the discharge frequency of the neurons and the ventral medulla of the ventral medulla (rostralventromedial medulla, RVMM) in the ventral medulla of the beak terminal ventrolateral medulla and the ventral medulla of the beak and the ventral medulla of the beak. The variation of the discharge frequency of the neurons in the ventral medulla of the ventromedial medulla (rostralventromedial medulla, RVMM) is mainly dependent on the excitatory response. However, the microinjection of CRF to the dorsal nucleus of the vagus nerve (dorsal motor) can be used in PH. The discharge activity of us nerve, DMNV) neurons has no effect. This result shows that PH is one of the important target areas for the central CRF energy system to regulate heart rate; the PH-RVLM/RVMM- cardiac sympathetic pathway, not the PH-DMNV- vagus pathway, is involved in mediating the tachycardia effect of central CRF. Two, PH orexin energy modulates the modulation of cardiovascular activity. In addition to the lateral hypothalamus and the fornix region, PH is also one of the important origins of the central orexin energy system. As a whole brain function regulator, the central orexin energy system not only participates in sleep awakening, energy balance, neuroendocrine, reward, emotional and physical regulation, but also regulates the cardiovascular activity of the body. It plays an important role. Since PH is also an important center for the regulation of cardiovascular activity, we have studied the central cardiovascular activity of orexin neurons in PH, and its neural loop and receptor, ion mechanism in this project. Our results show that the microinjection of orexin1 type receptor (OX1R) in the fourth brain is blocked. The agent (SB334867) and orexin 2 receptor (OX2R) blocker (TCSOX2 29) can significantly reduce the arterial blood pressure, tachycardia and renal sympathetic excitatory response induced by the bicuculline (GABAA receptor blocker) to inhibit the PH neurons, suggesting that the orexin neurons in PH are involved in the regulation of cardiovascular activity in PH. The immunofluorescence histochemical experiments showed that the orexin neurons in PH had moderate density nerve fibers projecting to the central RVMM of the brain stem and a very small projection of RVLM to the RVLM, and the microinjection of SB334867 or TCS OX2 29 in.RVMM could significantly weaken the suppression of PH induced pressor, tachycardia and the excitatory response of the renal sympathetic nerve. However, microinjection of SB334867 or TCS oX2 29 in RVLM had no blocking effect. The whole cell patch clamp recording of isolated brain slices showed that the two subtypes of orexin receptor OX1R and OX2R and the inward rectifier K~+ ion channels coupled with them, Na~+-Ca~ (2+) exchangers and non selective cation channels mediate the orexin on RVMM neurons. The results show that the orexin neurons in PH play an important role in the regulation of central cardiovascular activities, while orexin neurons in PH to RVMM, not RVLM, may mediate the cardiovascular regulation of PH.
【學位授予單位】：南京大學
【學位級別】：博士
【學位授予年份】：2016
【分類號】：Q42

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相關期刊論文 前1條

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本文編號：2008579