Excessive plasma dopamine increase at rest and during exercise after long-term beta-adrenoreceptor blockade in hypertensive patients.
Excessive plasma dopamine increase at rest and during exercise after long-term beta-adrenoreceptor blockade in hypertensive patients.
复制标题
高血压患者长期β-肾上腺素受体阻断后，静息时和运动时血浆多巴胺过多。
作者：
I. Franz;F. Lohmann;G. Koch
在7名25 ~ 51岁的中度高血压男性患者中，研究了心脏选择性β受体拮抗剂美托洛尔治疗4周和15个月对血压、血浆去甲肾上腺素、肾上腺素和多巴胺在静息时、亚最大稳态和接近最大运动时以及运动后5分钟的影响。4周的治疗导致静息时、运动期间和运动后的心率和血压显著降低;连续15个月后未观察到进一步的显著变化。治疗运动诱导的血浆去甲肾上腺素和肾上腺素的增加在美托洛尔治疗后趋于更明显，4周和15个月后的值几乎相同。血浆多巴胺受运动的影响要小得多，并且在工作期间仅表现出向较高值的微弱趋势。虽然在治疗四周后没有观察到显著变化，但在治疗15个月后，多巴胺比对照值显著增加10至12倍。在休息时，血浆多巴胺比相应的去甲肾上腺素和肾上腺素水平高5倍和10倍。多巴胺的过度升高可能具有临床意义：由于多巴胺的心血管和肾脏作用，高水平应倾向于抑制β受体阻滞剂的负性肌力作用，因此可能导致心输出量增加和外周血管阻力降低，这在长期治疗后与急性或短期给药相比，通常在β受体拮抗剂治疗后观察到。降压
SUMMARY The effect of four weeks and 15 months of treatment with the cardioselective beta-receptor antagonist metoprolol on blood pressures, plasma noradrenaline, adrenaline, and dopamine at rest, during submaximal steady state and near maximal exercise, as well as five minutes after exercise, was studied in seven moderately hypertensive men aged 25 to 51 years. Four weeks of treatment resulted in significantly lower heart rates and blood pressures at rest, during, and after exercise; no further significant changes were observed after 15 months of continuous. treatment. The exercise-induced increase in plasma noradrenaline and adrenaline tended to be more pronounced after treatment with metoprolol with virtually identical values after both four weeks and 15 months. Plasma dopamine was much less affected by exercise and showed only a weak tendency towards higher values during work. While no significant changes were observed after four weeks of treatment, there was a significant 10 to 12 fold increase of dopamine over the control values after 15 months of treatment. At rest plasma dopamine was five and 10 times higher than corresponding noradrenaline and adrenaline levels. The excessive rise of dopamine might have clinical implications: because of the cardiovascular and renal actions of dopamine, high levels should tend towards dampening the negative inotropic effect of beta-receptor blockade and might thus contribute to the increase of cardiac output and decrease of peripheral vascular resistance usually seen with beta-receptor antagonists after long-term treatment compared with acute or short-term administration. Antihypertensive