β-肾上腺素受体增强α<em>1</em>-肾上腺素受体介导的大鼠左心耳正性变力效应

• 作者: Ming-zhe CHEN Qi-de HAN 张幼怡 张永珍
• 来源期刊: 中国药理学报（英文版）
• 学科: 医学
• 关键词: alpha-1 adrenergic receptors beta adrenergic receptors heart atrium cardiac inotropism inositolphosphates adrenergic receptor antagonists adrenergic agonists
• 年，卷（期）: 2004,（1）
• 所属期刊栏目: 研究原著
• 页码范围: 29-34
• 页数: 6页
• 分类号: R54
• 语种: 英文

摘要

AIM: To investigate whether stimulation of β-adrenoceptor (AR) and its subtypes augment α1-AR-evoked positive inotropic response and inositol phosphate (InsP) accumulation in isolated rat left atria. METHODS: Inotropic response was determined by contractile function experiment in isolated electrically driven rat left atria. 3H-InsP accumulations were measured by 3H-inositol incorporation and column chromatography. RESULTS: (1) Stimulation of α1-AR by phenylephrine (PE) or norepinephrine (NE) in the presence of propranolol (Prop) evoked positive inotropic response and 3H-InsP accumulations, while stimulation of β-AR by isoprenaline (ISO) or NE in the presence of phentolamine (Phen) only evoked positive inotropic response, but not 3H-InsP accumulations. (2) Simultaneous stimulation of α1- and β-AR by NE or ISO plus PE significantly shifted the concentration-dependent inotropic response curves and 3H-InsP accumulation curves to the left and upward compared with individual α1-AR stimulation by PE or NE in the presence of Prop. (3) In the presence of ICI118551 (selective β2-AR antagonist) or CGP12177 (selective β1-AR antagonist), stimulation of either β1- or β2-AR did not change α1-AR-evoked inotropic response and 3H-InsP accumulations. CONCLUSION: Stimulation of β1-AR and β2-AR potentiates α1-AR-mediated positive inotropic response and InsP accumulation in isolated rat left atria.