The Role of Alpha-Adrenoceptor Subtype on Microvessels

α-肾上腺素受体亚型对微血管的作用

• 批准号: 03670469
• 负责人: OHYANAGI Mitsumasa
• 金额: $ 1.41万
• 依托单位: Hyogo College of Medicine
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1991
• 资助国家: 日本
• 起止时间: 1991 至 1992
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-03670469/
• 关键词: alpha-adrenoceptor; subtype; microcirculation; SHR; myogenic response; in vitro; myogenic response; αーadrenergic receptor

Hyperresponsiveness of vascular smooth muscle to alpha-AR-mediated vasoconstriction has been proposed as a factor involved in maintenance of the elevated vascular resistance in hypertensive state. alpha AR constriction can be mediated by two types of alpha-AR, alpha-1 and alpha-2. No conclusive evidence has been demonstrate in which subtype of alpha-AR playesmainly the role on maintenance of peripheral resistance in hypertensive rats (SHR). The sensitivity of alpha-AR of resistance large arteriole was examined with in vitro videomicroscopy in prehypertensive(4-5 week) and early hypertensive stage(7-8 week) of SHR compared with age mayched WKY. Microdissected vessels were double-cannulated with glass micropipets in a tissue bath. Norepinephrine (NE) concentration-response curves were obtained in the presence of prazosine or rauwolscine to establish the concentrations of NE required to selectivity stimulate alpha-1 or alpha-2 AR. The sensitivity to alpha-1 constriction was much greater in SHR than WKY in both stage. There was no difference in alpha-2 constriction between SHR and WKY. We also examined to explore which alpha subtype has a greater sensitivity to myogenic modulation in SHR. Myogenic constriction during in lumen pressure was greater during alpha-2 than alpha-1. These finding suggested that hypersensitivity of alphaAR to vasoconstriction play a role on maintenance or etiologic factor in elevated vascular resistance in hypertension.

血管平滑肌对α-AR介导的血管收缩的高反应性被认为是维持高血压状态下血管阻力升高的一个因素。α-AR收缩可由两种类型的α-AR介导，即α-1和α-2。目前尚无确凿证据表明α-AR亚型在维持高血压大鼠(SHR)外周阻力中起主要作用。用体外摄像显微镜检测高血压前期(4~5周)和高血压早期(7~8周)阻力大动脉α-AR的敏感性，并与年龄相关的WKY进行比较。在组织浴中用玻璃微管对显微解剖的血管进行双重插管。用去甲肾上腺素(NE)浓度-反应曲线测定去甲肾上腺素(NE)选择性刺激α1或α2受体所需的浓度。在这两个阶段，SHR对α-1收缩的敏感性明显高于WKY。SHR和WKY的α-2收缩无差异。我们还研究了哪种阿尔法亚型对自发性高血压患者的肌源性调节更敏感。腔内压力时的肌源性收缩在α-2阶段大于α-1阶段。这些结果提示，αAR对血管收缩的超敏反应在高血压血管阻力升高的维持或病因中起作用。

项目成果

大柳 光正,渋谷 純,池岡 清光,西垣 和光,岩崎 忠昭: "抵抗血管におけるmyogenic responseに対するαーアドレナリン受容体の役割ーin vitroでの研究ー" 脈管学.

Mitsumasa Oyanagi、Jun Shibuya、Kiyomitsu Ikeoka、Kazumitsu Nishigaki、Tadaaki Iwasaki：“α-肾上腺素受体对阻力血管肌源性反应的作用 - 体外研究”血管学。

渋谷 純 他: "高血圧初期の高血圧自然発症ラットにおける抵抗血管の内圧上昇に対する収縮反応" 脈管学. 32. 964- (1992)

Jun Shibuya 等人：“高血压早期自发性高血压大鼠对阻力血管内压升高的收缩反应。” 32. 964- (1992)。

渋谷 純,他: "高血圧初期の高血圧自然発症ラットにおける抵抗血管の内圧上昇に対する収縮反応" 脈管学. 32. 964- (1992)

Jun Shibuya 等：“高血压早期自发性高血压大鼠对阻力血管内压增加的收缩反应”Angiology 32. 964- (1992)。

Shibuya J: "The constrictic response to increased lumen pressure of resistance arteriole of early stage spontaneously hypertensive rats" Angiology (Japanese). 32. 964 (1992)

Shibuya J：“早期自发性高血压大鼠抵抗小动脉管腔压力增加的收缩反应”血管学（日语）。