Brenna S, Thonney Viani M, Drukker A, Guignard J P
Division of Nephrology, Department of Pediatrics, University Medical Center Lausanne, Switzerland.
Biol Neonate. 1998 Dec;74(6):451-6. doi: 10.1159/000014067.
The aim of this study was to investigate the acute, short-term effects of the intravenous (i.v.) administration of magnesium (Mg) sulfate on renal function in the newborn rabbit. Eight anesthetized and mechanically ventilated, normoxemic, newborn New Zealand white rabbits were studied. We measured mean arterial blood pressure (MAP), urine volume (V), glomerular filtration rate (GFR), renal plasma flow (RPF) and calculated renal blood flow, filtration fraction (FF) and renal vascular resistance (RVR) under control conditions and in two experimental periods after the i.v. Mg sulfate load. Mg sulfate administration in a dose 100 mg/kg followed by 50 mg/kg/h caused a significant fall (p < 0.001) in MAP, GFR and RPF, whereas the RVR increased (p < 0.01). FF did not change significantly (p: NS/0.05) and V remained constant. These results show that the acute i.v. administration of Mg sulfate to newborn rabbits causes systemic vasodilatation with a fall in MAP. The increase in RVR, without consistent change in FF, suggests that the renal vasculature of the 'immature' neonatal rabbit reacts to these changes by preferential afferent arteriolar vasoconstriction.
本研究旨在探讨静脉注射硫酸镁对新生兔肾功能的急性短期影响。对8只麻醉、机械通气、血氧正常的新生新西兰白兔进行了研究。我们在对照条件下以及静脉注射硫酸镁负荷后的两个实验阶段测量了平均动脉血压（MAP）、尿量（V）、肾小球滤过率（GFR）、肾血浆流量（RPF），并计算了肾血流量、滤过分数（FF）和肾血管阻力（RVR）。以100mg/kg的剂量静脉注射硫酸镁，随后以50mg/kg/h的速度注射，导致MAP、GFR和RPF显著下降（p<0.001），而RVR升高（p<0.01）。FF无显著变化（p：无显著性差异/0.05），V保持恒定。这些结果表明，给新生兔静脉注射硫酸镁会导致全身血管扩张，MAP下降。RVR升高，而FF无一致变化，这表明“未成熟”新生兔的肾血管系统通过优先的入球小动脉收缩对这些变化作出反应。
