Vlachakis N D, Barr J, Velasquez M, Alexander N, Maronde R
Clin Pharmacol Ther. 1984 Jun;35(6):782-7. doi: 10.1038/clpt.1984.112.
A single oral dose of 300 mg labetalol was given to 10 subjects with uncomplicated primary hypertension; its effects on blood pressure, heart rate (HR), plasma renin activity (PRA), and plasma concentration of catecholamines and of their major metabolites, octopamine ( OTP ), and dopamine-beta hydroxylase (DbH) were investigated. Although HR did not change after dosing, both systolic and diastolic blood pressure decreased in 2 hr and remained below control up to 12 hr. There was symptomatic orthostatic hypotension in two subjects in the first 2 hr after dosing. PRA decreased in the first 2 hr and followed a gradual rise that became significant at 24 hr. Although DbH did not change, plasma concentrations of norepinephrine (NE) and its major metabolites and of OTP increased between 2 and 4 hr after dosing and remained elevated up to 12 hr. There was no correlation between change in blood pressure and control levels or changes of PRA or NE concentrations.
给10例无并发症的原发性高血压患者单次口服300mg拉贝洛尔；研究了其对血压、心率（HR）、血浆肾素活性（PRA）、血浆儿茶酚胺及其主要代谢产物去甲辛弗林（OTP）和多巴胺-β-羟化酶（DbH）浓度的影响。给药后HR虽未改变，但收缩压和舒张压在2小时内均下降，并在12小时内一直低于对照值。给药后最初2小时内有2例患者出现症状性体位性低血压。PRA在最初2小时内下降，随后逐渐上升，在24小时时变得显著。尽管DbH未改变，但给药后2至4小时内去甲肾上腺素（NE）及其主要代谢产物以及OTP的血浆浓度升高，并一直升高至12小时。血压变化与对照水平或PRA或NE浓度变化之间无相关性。
