Van Hamersvelt H W, Wetzels J F, Kloke H J, Koene R A, Huysmans F T
Department of Medicine, Sint Radboud Hospital, University of Nijmegen, The Netherlands.
Am J Physiol. 1994 Jun;266(6 Pt 2):F843-9. doi: 10.1152/ajprenal.1994.266.6.F843.
Calcium entry blockers, such as felodipine, increase natriuresis without increasing kaliuresis. Since these drugs acutely increase plasma renin activity without a concomitant change of aldosterone, inhibition of such stimulated aldosterone release might explain the absence of kaliuresis. In a randomized crossover study in 12 male volunteers, we compared the effects of simultaneously administered exogenous aldosterone and felodipine with the effects of either felodipine or aldosterone alone. Felodipine infusion decreased blood pressure, increased renal plasma flow, and induced natriuresis without kaliuresis. Aldosterone alone reduced sodium excretion and increased potassium excretion without influencing hemodynamics. Addition of aldosterone to felodipine attenuated its natriuretic effect and induced a kaliuresis, which clearly exceeded the rise of potassium excretion during aldosterone alone [delta% fractional excretion of K+ +42 +/- 12 with felodipine+aldosterone and +7 +/- 8% with aldosterone alone; means +/- SE, P < 0.02]. Our data suggest that felodipine-mediated inhibition of stimulated aldosterone release is essential for the absence of kaliuresis with felodipine. In addition, the pronounced kaliuresis with aldosterone during felodipine is in keeping with increased distal sodium delivery due to a proximal tubular action of felodipine.
钙通道阻滞剂，如非洛地平，可增加尿钠排泄而不增加尿钾排泄。由于这些药物可急性增加血浆肾素活性而不伴有醛固酮的相应变化，抑制这种受刺激的醛固酮释放可能解释了尿钾排泄缺乏的原因。在一项对12名男性志愿者进行的随机交叉研究中，我们比较了同时给予外源性醛固酮和非洛地平的效果与单独使用非洛地平或醛固酮的效果。输注非洛地平可降低血压、增加肾血浆流量并诱导尿钠排泄而无尿钾排泄。单独使用醛固酮可减少钠排泄并增加钾排泄而不影响血流动力学。在非洛地平中加入醛固酮可减弱其利钠作用并诱导尿钾排泄，这明显超过了单独使用醛固酮时钾排泄的增加[非洛地平 + 醛固酮时钾离子分数排泄增加百分比为 +42 ± 12，单独使用醛固酮时为 +7 ± 8%；均值 ± 标准误，P < 0.02]。我们的数据表明，非洛地平介导的对受刺激醛固酮释放的抑制对于非洛地平无尿钾排泄至关重要。此外，在非洛地平存在时醛固酮引起的明显尿钾排泄与非洛地平近端肾小管作用导致的远端钠输送增加一致。
