Bevilacqua M, Norbiato G, Raggi U, Micossi P, Baggio E, Prandelli M
Metabolism. 1980 Apr;29(4):306-10. doi: 10.1016/0026-0495(80)90002-5.
Metoclopramide, a dopaminergic inhibitor, injected in 9 normal volunteers, was followed by a prompt decrease of serum potassium (10--20 min; p less than 0.01) and by an increase of plasma aldosterone (p less than 0.01). Renin slightly increased at 45 min (p less than 0.05); insulin and cortisol did not show any significant increase. The urinary excretion of potassium rose after metoclopramide (p less than 0.05). A bolus of aldosterone (250 micrograms i.v.) in 4 normal subjects was not followed by any modification of serum potassium, but increased urinary potassium excretion (p less than 0.05); the injection of metoclopramide in two patients with an aldosterone-secreting adenoma of the adrenal and in one patient with Addison's disease induced a decrease of serum potassium in absence of any modification of plasma aldosterone. The decrease of serum potassium after metoclopramide is not explained by changes of aldosterone or insulin, considered the most important hormonal controls of potassium. The rapidity of potassium decrease implies a change of distribution of potassium between extra- and intracellular compartments, which, in turn, may stimulate aldosterone secretion. It is conceivable that the dopaminergic system has a role in the control of serum potassium.
甲氧氯普胺是一种多巴胺能抑制剂，给9名正常志愿者注射后，血清钾迅速下降（10 - 20分钟；p < 0.01），血浆醛固酮增加（p < 0.01）。肾素在45分钟时略有增加（p < 0.05）；胰岛素和皮质醇未见明显增加。甲氧氯普胺注射后尿钾排泄增加（p < 0.05）。给4名正常受试者静脉注射大剂量醛固酮（250微克）后，血清钾无任何变化，但尿钾排泄增加（p < 0.05）；给2例肾上腺醛固酮分泌腺瘤患者和1例艾迪生病患者注射甲氧氯普胺后，血清钾下降，而血浆醛固酮无任何变化。甲氧氯普胺注射后血清钾下降不能用醛固酮或胰岛素的变化来解释，醛固酮和胰岛素被认为是钾最重要的激素调节因素。钾下降的迅速性意味着细胞外和细胞内钾分布的改变，这反过来可能刺激醛固酮分泌。可以想象，多巴胺能系统在血清钾的调节中起作用。
