Temperature dependence of [3H]dihydroalprenolol binding in rat myocardium.
Temperature dependence of [3H]dihydroalprenolol binding in rat myocardium.
复制标题
[3H]二氢阿普洛尔在大鼠心肌中结合的温度依赖性。
DOI：
10.1016/0014-2999(82)90001-2
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发表时间：
1982
影响因子：
5
通讯作者：
Bhalla,R
中科院分区：
文献类型：
--
作者：
Winek,R;Bhalla,R
The β-adrenergic antagonist, [3H]dihydroalprenolol, was used to label binding sites in crude rat myocardial plasma membranes. The specificity of binding was dependent on the temperature of the assay. Specific binding at 22 and 37°C and at concentrations of radioligand less than 5 nM was consistent with binding to the myocardial β-receptor. Binding sites labeled at 4°C possessed quite different properties. Binding was non-stereoselective and of lower affinity. Agonist compounds were much less effective at competing for the labeled myocardial sites at 4°C than at 22°C. Those β-antagonists which additionally possess pharmacological ‘quinidine-like’ activity (e.g. propranolol, alprenolol) were potent competitors at 4°C, but competition was non-stereoselective. In contrast atenolol, a β-antagonist devoid of ‘quinidine-like’ activity was ineffective at 4°C. Furthermore, procaine, and quinidine itself were potent competitors of [3H]dihydroalprenolol binding at 4°C. Thus the specificity of [3H]dihydroalprenolol binding to rat heart membranes at 4°C appears to be directed non-stereoselectively at that portion of the competing molecule which recognized ‘quinidine-like’ as opposed to adrenergic activity.
