Rosa R M, Silva P, Young J B, Landsberg L, Brown R S, Rowe J W, Epstein F H
N Engl J Med. 1980 Feb 21;302(8):431-4. doi: 10.1056/NEJM198002213020803.
We studied the role of catecholamines in the regulation of potassium homeostasis in nine healthy subjects given intravenous potassium chloride (0.5 meq per kilogram of body weight) in the presence and absence of propranolol. Potassium infusion elevated serum potassium 0.6 +/- 0.09 meq per liter (mean +/-S.E.M.). Addition of propranolol augmented the rise (0.9 +/- 0.05 meq per liter) and prolonged the elevation in serum potassium without decreasing urinary potassium excretion. In a separate study, the same potassium load was administered with a concomitant infusion of epinephrine in five subjects. Epinephrine markedly blunted the increment in serum potassium (0.1 +/- 0.06 meq per liter) while reducing renal potassium excretion. Plasma aldosterone was not altered by the experimental procedures. Serum insulin fell minimally in the presence of propranolol but was unaffected by epinephrine. beta-Adrenergic blockade impairs and epinephrine enhances extrarenal disposal of an acute potassium load. These findings suggest that in patients with impaired potassium disposal, the risk of hyperkalemia may be increased when sympathetic blockade is induced.
我们研究了儿茶酚胺在9名健康受试者钾稳态调节中的作用，这些受试者在有和没有普萘洛尔的情况下静脉注射氯化钾（每公斤体重0.5毫当量）。输注钾使血清钾升高0.6±0.09毫当量/升（平均值±标准误）。添加普萘洛尔会增强升高幅度（0.9±0.05毫当量/升）并延长血清钾升高时间，且不降低尿钾排泄。在另一项研究中，对5名受试者同时输注肾上腺素并给予相同的钾负荷。肾上腺素显著减弱血清钾的升高幅度（0.1±0.06毫当量/升），同时减少肾钾排泄。实验过程未改变血浆醛固酮水平。在普萘洛尔存在的情况下血清胰岛素略有下降，但不受肾上腺素影响。β-肾上腺素能阻断会损害而肾上腺素会增强急性钾负荷的肾外处置。这些发现表明，在钾处置受损的患者中，诱导交感神经阻断时高钾血症风险可能增加。
