Koike K, Takayanagi I
Jpn J Pharmacol. 1986 Oct;42(2):325-8. doi: 10.1254/jjp.42.325.
Interactions of beta-adrenergic partial agonists with the beta-adrenoceptor were studied in isolated guinea-pig taenia caecum. The competitive inhibition curve for specific binding of a high concentration (50 nM) of [3H]-befunolol by befunolol showed a biphasic shape, although the curve for specific binding of a low concentration (1 nM) was monophasic. All the competitive inhibition curves for specific binding of [3H]-befunolol (1 nM and 50 nM) by isoprenaline and propranolol showed monophasic shapes. These results suggest that befunolol may be able to discriminate two different binding sites of the beta-adrenoceptor: the high affinity site and the low affinity site.
在离体豚鼠盲肠带中研究了β-肾上腺素能部分激动剂与β-肾上腺素受体的相互作用。倍他洛尔对高浓度（50 nM）[3H]-倍他洛尔特异性结合的竞争抑制曲线呈双相，而低浓度（1 nM）特异性结合的曲线呈单相。异丙肾上腺素和普萘洛尔对[3H]-倍他洛尔（1 nM和50 nM）特异性结合的所有竞争抑制曲线均呈单相。这些结果表明，倍他洛尔可能能够区分β-肾上腺素受体的两个不同结合位点：高亲和力位点和低亲和力位点。
