Kumana C R, Kaye C M, Leighton M, Marlin G E
Eur J Clin Pharmacol. 1977 Aug 17;12(1):7-13. doi: 10.1007/BF00561399.
In a group of 6 healthy (but physically unfit) volunteers an investigation was made of whether there was a true plasma level effect relationship and absolute "cardioselectivity" with respect to beta-adrenoceptor blockade due to practolol. To this end three treatments were given orally, namely placebo, practolol 100 mg and practolol 400 mg. Cardiac beta-adrenoceptor blockade was assessed by measuring the inhibition of exercise heart rate and pulmonary beta-adrenoceptor blockade was assessed by measuring the reduction in exercise peak flow rate, up to 24 h after each dose. Plasma practolol levels were determined spectrophotometrically. From the results obtained there was no reason to doubt the existence of a valid relationship between cardiac beta-adrenoceptor blocking activity and the plasma concentration of practolol. It was also concluded that even in non-asthmatics, practolol does not possess absolute "cardioselectivity" since significant reductions in peak flow rate were discernible during vigorous exercise, particularly when the large dose had been given.
在一组6名健康（但身体不健康）的志愿者中，对心得宁引起的β-肾上腺素能受体阻滞是否存在真正的血浆水平效应关系和绝对“心脏选择性”进行了研究。为此，口服给予三种治疗，即安慰剂、100毫克心得宁和400毫克心得宁。通过测量运动心率的抑制来评估心脏β-肾上腺素能受体阻滞，通过测量每次给药后长达24小时的运动峰值流速降低来评估肺部β-肾上腺素能受体阻滞。用分光光度法测定血浆心得宁水平。从获得的结果来看，没有理由怀疑心脏β-肾上腺素能受体阻断活性与心得宁血浆浓度之间存在有效关系。还得出结论，即使在非哮喘患者中，心得宁也不具有绝对“心脏选择性”，因为在剧烈运动期间，尤其是给予大剂量时，可明显看出峰值流速显著降低。
