Valentin J P, Ribstein J, Mimran A
Department of Medicine, Hôpital Lapeyronie, CHU, Montpellier, France.
J Cardiovasc Pharmacol. 1994 Feb;23(2):246-51.
Unilateral nephrectomy (UNX) is followed by a prompt functional adaptation (as well as initiation of compensatory growth) in the contralateral kidney. We assessed the possibility that dopamine (DA) receptor antagonism and angiotensin-converting enzyme inhibition may influence the acute natriuretic response to UNX of the remaining kidney in euvolemic anesthetized Sprague-Dawley rats with or without pretreatment by haloperidol or enalapril. Twenty to 80 min after UNX, urinary excretion of sodium and potassium approximately doubled and fractional excretion of lithium (an index of proximal tubular handling of sodium) increased by about one third in untreated rats, whereas glomerular filtration rate, renal plasma flow and mean arterial pressure (MAP) did not change significantly. Haloperidol infusion blunted the post-UNX increase in fractional excretion of lithium without affecting the natriuretic/kaliuretic response of the remaining kidney. Enalapril pretreatment resulted in lower MAP and marked renal vasodilation at baseline but no significant alteration in the response to UNX. These results indicate that the magnitude of post-UNX natriuresis is not affected by suppression of angiotensin II (AII) generation or blockade of DA receptors. The lithium clearance data suggest that the immediate natriuretic response to UNX can be ascribed to both a proximal and a distal tubular phenomenon.
单侧肾切除术后，对侧肾脏会迅速发生功能适应（以及启动代偿性生长）。我们评估了多巴胺（DA）受体拮抗和血管紧张素转换酶抑制是否会影响等容麻醉的Sprague-Dawley大鼠在单侧肾切除术后对剩余肾脏的急性利钠反应，这些大鼠在有或没有接受氟哌啶醇或依那普利预处理的情况下。单侧肾切除术后20至80分钟，未处理的大鼠尿钠和尿钾排泄量约增加一倍，锂的排泄分数（近端肾小管对钠处理的指标）增加约三分之一，而肾小球滤过率、肾血浆流量和平均动脉压（MAP）无明显变化。输注氟哌啶醇减弱了单侧肾切除术后锂排泄分数的增加，但不影响剩余肾脏的利钠/利尿反应。依那普利预处理导致基线时MAP降低和明显的肾血管舒张，但对单侧肾切除术后的反应无显著改变。这些结果表明，单侧肾切除术后利钠作用的幅度不受血管紧张素II（AII）生成抑制或DA受体阻断的影响。锂清除率数据表明，对单侧肾切除术后的即时利钠反应可归因于近端和远端肾小管现象。
