Gratama J W, Dalinghaus M, Meuzelaar J J, Gerding A M, Koers J H, Zijlstra W G, Kuipers J R
Department of Pediatrics, University of Groningen, The Netherlands.
J Clin Invest. 1992 Nov;90(5):1745-52. doi: 10.1172/JCI116048.
A left-to-right shunt is accompanied by an increased plasma and blood volume. Since this is likely realized through renin/aldosterone-mediated salt and water retention, other body fluid compartments may be changed too. Therefore, we studied blood volume and body fluid compartments by a single-injection, triple-indicator dilution technique in nine 8-wk-old lambs with an aortopulmonary left-to-right shunt (55 +/- 3% of left ventricular output; mean +/- SEM) and in 11 control lambs, 2.5 wk after surgery. Systemic blood flow was maintained at the same level as in control lambs, but the aortic pressure of the shunt lambs was lower. Blood volume in shunt lambs was larger than in control lambs (110 +/- 6 vs. 84 +/- 7 ml/kg, P < 0.001) through an increase in plasma volume, which correlated significantly with the magnitude of the left-to-right shunt (r = 0.81, P < 0.01). Red blood cell volume was equal to that of control lambs. Evidence was obtained that the increase in plasma volume was induced by a transient increase in renin (8.0 +/- 2.2 vs. 1.6 +/- 0.2 nmol.l-1.h-1; P < 0.02) and aldosterone (0.51 +/- 0.14 vs. 0.24 +/- 0.09 nmol/liter) concentrations. Interstitial water volume, however, was not significantly different from that in control lambs. The amount of intravascular protein was significantly higher than in control lambs (5.0 +/- 0.3 vs. 3.5 +/- 0.2 g/kg body mass, P < 0.001). There were no significant differences in intracellular and total body water volumes between the two groups. We conclude that the increased amount of intravascular protein confines the fluid retained by the kidneys to the vascular compartment.
左向右分流伴有血浆量和血容量增加。由于这可能是通过肾素/醛固酮介导的盐和水潴留实现的，其他体液成分也可能发生变化。因此，我们采用单注射、三指示剂稀释技术，对9只8周龄患有主肺动脉左向右分流（占左心室输出量的55±3%；平均值±标准误）的羔羊和11只对照羔羊在术后2.5周时的血容量和体液成分进行了研究。分流羔羊的全身血流维持在与对照羔羊相同的水平，但分流羔羊的主动脉压较低。通过血浆量增加，分流羔羊的血容量大于对照羔羊（110±6 vs. 84±7 ml/kg，P<0.001），且血浆量增加与左向右分流的程度显著相关（r = 0.81，P<0.01）。红细胞体积与对照羔羊相等。有证据表明，血浆量增加是由肾素（8.0±2.2 vs. 1.6±0.2 nmol·l-1·h-1；P<0.02）和醛固酮（0.51±0.14 vs. 0.24±0.09 nmol/l）浓度短暂升高引起的。然而，间质水体积与对照羔羊无显著差异。血管内蛋白质含量显著高于对照羔羊（5.0±0.3 vs. 3.5±0.2 g/kg体重，P<0.001）。两组之间细胞内和总体水体积无显著差异。我们得出结论，血管内蛋白质含量增加将肾脏潴留的液体限制在血管腔内。
