Blumberg A L, Dubb J W, Allison N L, Aldins Z, Ramey K, Stote R M
Presbyterian-University of Pennsylvania Medical Center, Smith Kline & French Laboratories, Philadelphia 19104.
J Cardiovasc Pharmacol. 1988 Feb;11(2):181-6.
The purpose of the present study was to evaluate the effect on renal function of dopamine (low dose, 2 micrograms/kg/min) inhibition by a low-dose infusion of metoclopramide. Prolactin and aldosterone levels were measured to assess metoclopramide's endocrine effects. Six salt-loaded subjects were studied by standard renal clearance techniques during water diuresis. Dopamine infusion produced an increase in renal plasma flow, fractional excretion of sodium, osmolar and free water clearances, urine volume, and solute delivery out of the proximal tubule. Solute and fluid absorption decreased in the distal nephron. These effects were evident within the first hour and peaked during the third hour. Metoclopramide slightly attenuated the dopamine-induced increase in renal plasma flow; statistical significance was obtained only during the second hour. None of the other renal function changes were inhibited. Serum prolactin and aldosterone levels were significantly increased following metoclopramide. Dopamine infusion attenuated the rise in prolactin levels but did not significantly affect aldosterone levels. The variance between previous reports and the present one may be due to the use of water diuresis, salt-loading, or methodological factors. Metoclopramide infused at 0.1 mg/kg/h appears selective for DA2 receptors, and low-dose dopamine-induced changes in renal function are DA1 receptor-mediated.
本研究的目的是评估低剂量输注甲氧氯普胺对多巴胺（低剂量，2微克/千克/分钟）抑制肾功能的影响。测量催乳素和醛固酮水平以评估甲氧氯普胺的内分泌作用。在水利尿期间，通过标准肾清除技术对6名盐负荷受试者进行了研究。输注多巴胺使肾血浆流量、钠分数排泄、渗透和自由水清除率、尿量以及近端小管溶质排出量增加。远端肾单位的溶质和液体吸收减少。这些效应在第一小时内明显，并在第三小时达到峰值。甲氧氯普胺略微减弱了多巴胺诱导的肾血浆流量增加；仅在第二小时获得统计学意义。其他肾功能变化均未受到抑制。甲氧氯普胺后血清催乳素和醛固酮水平显著升高。输注多巴胺减弱了催乳素水平的升高，但对醛固酮水平没有显著影响。先前报告与本报告之间的差异可能归因于水利尿、盐负荷或方法学因素的使用。以0.1毫克/千克/小时输注的甲氧氯普胺似乎对DA2受体具有选择性，低剂量多巴胺诱导的肾功能变化是由DA1受体介导的。
