Takayanagi I, Konno F, Kameda H, Kubo H, Furukawa A, Toyoda T
Jpn J Pharmacol. 1986 Dec;42(4):579-82. doi: 10.1254/jjp.42.579.
Optical isomers of YM-12617, a potent and selective alpha 1-adrenoceptor blocker, were tested on the rabbit iris dilator and aorta. The order of potency was R(-)-isomer greater than racemate greater than S(+)-isomer. The R(-)-isomer and racemate behaved as an essentially irreversible antagonist to norepinephrine in the iris dilator where the efficacy of norepinephrine was small, although the S(+)-isomer was a competitive antagonist. These drugs behaved as a competitive antagonist of norepinephrine in the aorta where the efficacy of norepinephrine was large.
强效选择性α1肾上腺素受体阻滞剂YM-12617的光学异构体在兔虹膜开大肌和主动脉上进行了测试。效价顺序为R(-)-异构体＞消旋体＞S(+)-异构体。在虹膜开大肌中，去甲肾上腺素的效能较小，R(-)-异构体和消旋体表现为对去甲肾上腺素的基本不可逆拮抗剂，而S(+)-异构体是竞争性拮抗剂。在主动脉中，去甲肾上腺素的效能较大，这些药物表现为去甲肾上腺素的竞争性拮抗剂。
