Commarato M A, Giardino E C, Kopia G A, Kaplan H R
Arch Int Pharmacodyn Ther. 1977 Apr;226(2):205-13.
The oral beta-adrenoceptor blocking activity of bunolol, propanolol, and their levo-isomers was compared against isoproterenol- and treadmill exercise-induced tachycardias in normal conscious dogs. Relative potencies against isoproterenol were (ascending order): propranolol=1, levo-propranolol=2, bunolol=40, and levo-bunolol=102. Large oral doses of levo-bunolol and propranolol suppressed exercise tachycardia by only 18% (range 10 to 22%). Compared to the isoproterenol response, the tachycardia associated with severe exercise in the healthy trained dog was largely resistant to beta-receptor blockade showing factors other than beta-receptor stimulation to be involved. Differences in duration of beta-blockade were observed at equiactive doses of levo-bunolol and propranolol. The isoproterenol response had returned to greater than 50% of control by 12 hr after propranolol but was less than 10% of control at 12 hr after levo-bunolol. The time to 50% recovery of the exercise tachycardia was 24 hr after levo-bunolol and 6 to 9 hr after propranolol. The results show oral levo-bunolol to be considerably more potent and to have a longer duration of action than propranolol in inhibiting both isoproterenol and exercise-induced tachycardias in conscious dogs.
在正常清醒犬中，比较了布诺洛尔、普萘洛尔及其左旋异构体对异丙肾上腺素和跑步机运动诱发心动过速的口服β肾上腺素受体阻断活性。对异丙肾上腺素的相对效价（升序排列）为：普萘洛尔=1，左旋普萘洛尔=2，布诺洛尔=40，左旋布诺洛尔=102。大剂量口服左旋布诺洛尔和普萘洛尔仅使运动性心动过速抑制18%（范围为10%至22%）。与异丙肾上腺素反应相比，健康训练犬中与剧烈运动相关的心动过速对β受体阻断有很大抗性，表明除β受体刺激外还有其他因素参与。在左旋布诺洛尔和普萘洛尔等活性剂量下观察到β阻断持续时间的差异。普萘洛尔给药12小时后，异丙肾上腺素反应恢复到对照值的50%以上，但左旋布诺洛尔给药12小时后，该反应低于对照值的10%。左旋布诺洛尔作用后运动性心动过速恢复到50%的时间为24小时，普萘洛尔作用后为6至9小时。结果表明，在抑制清醒犬的异丙肾上腺素和运动诱发的心动过速方面，口服左旋布诺洛尔比普萘洛尔效力更强且作用持续时间更长。
