INHIBITION OF [3H]‐DIHYDROALPRENOLOL BINDING TO RAT CARDIAC MEMBRANES BY VARIOUS β‐BLOCKING AGENTS
INHIBITION OF [3H]‐DIHYDROALPRENOLOL BINDING TO RAT CARDIAC MEMBRANES BY VARIOUS β‐BLOCKING AGENTS
复制标题
各种β-阻断剂对[3H]-二氢丙烯洛尔与大鼠心肌膜结合的抑制
DOI：
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发表时间：
1978
期刊：
影响因子：
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通讯作者：
H. Schmitt
中科院分区：
文献类型：
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作者：
P. CHENIEUX‐GUICHENEY;J. Dausse;P. Meyer;H. Schmitt
1[~3H]-二氢阿普洛尔与大鼠心肌细胞膜的结合是快速可逆的(Fcj=0.633~0.701×106m_1 S_1，Fc_x=0.0017~0.0043 S_1)。2[~3H]-DHA与单一结合部位结合，平衡离解常数(K_(25)C)为5.7±1.1×10~(-1)−~9M。3这种结合是特异的，肾上腺素受体激动剂竞争结合位点的效力顺序为(-)-异丙肾上腺素；(±)-异丙肾上腺素；(+)-异丙肾上腺素；(-)-肾上腺素；(-)-去甲肾上腺素。这与心脏β受体的β1性质是一致的。与其他阻滞剂相比，4种心脏选择性β阻滞剂(即美托洛尔、乙酰丁洛尔和心得安)的结合位点亲和力较低。这可能与这些分子芳香端侧链的空间位阻有关。
1 Binding of [3H]‐dihydroalprenolol ([3H]‐DHA) to rat cardiac membranes was rapid and reversible (fcj = 0.633‐0.701 × 106M_1 s_1 and fc_x = 0.0017‐0.0043 s_1). 2 [3H]‐DHA bound to a single class of binding sites with an equilibrium dissociation constant (Kd25°c) Of 5.7 ± 1.1 × 10−9M. 3 This binding was specific and the order of potency of adrenoceptor agonists in competing for the binding sites was (—)‐isoproterenol < (±)‐isoproterenol < (+)‐isoproterenol < (—)‐adrenaline < (—)‐noradrenaline. This was in agreement with the β1 nature of the cardiac β‐receptors. 4 Cardioselective β‐blockers (i.e. metoprolol, acebutolol and practolol) were shown to have lower binding site affinities, when compared to other blockers. This may be related to steric hindrance by the side‐chain at the aromatic end of these molecules.