Acute effects of angiotensin II on renal haemodynamics and excretion in conscious dogs.
Acute effects of angiotensin II on renal haemodynamics and excretion in conscious dogs.
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血管紧张素 II 对清醒犬肾血流动力学和排泄的急性影响。
DOI：
10.1159/000173197
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发表时间：
1989
期刊：
影响因子：
--
通讯作者：
G. Kaczmarczyk
中科院分区：
文献类型：
--
作者：
J. Keil;R. Lehnfeld;H. Reinhardt;R. Mohnhaupt;G. Kaczmarczyk
60分钟静脉滴注血管紧张素II的作用（A II; 4或20 ng A II/min/kg体重）对肾血流量的影响（RBF;电磁流量传感器，对照值19-25 ml/min/kg），肾小球滤过率（GFR;对照值4.2-5.0 ml/min/kg），平均动脉血压，钠排泄，水排泄，和血浆A II和血浆醛固酮浓度在6只长期装有仪器的清醒雌性比格犬中进行检测，这些比格犬保持三种不同的膳食钠摄入量（SI）：SI 0.5或SI 2.5 mmol Na/kg/天或SI 4.5 mmol Na/kg/天加实验前口服生理盐水负荷SI 4.5（+）犬。在SI 4.5（+）狗中，4纳克A II降低RBF和GFR，而不改变滤过分数（FF%）;在SI 0.5狗中，RBF降低，FF%增加。在所有饮食方案中，20纳克A II降低RBF并增加FF%，在SI 4.5（+）狗中较少。在所有饮食方案中，平均动脉血压增加了10-15 mm Hg（4 ng A II）和32-37 mm Hg（20 ng A II）。在两种A II剂量下，SI 4.5（+）犬的钠和水排泄量分别降低32%和46%。除一种方案外，所有方案的血浆醛固酮浓度均升高：4 ng A II，SI 4.5（+）犬。可以得出结论，当A II血浆浓度最有可能接近病理生理条件（平均值高达370 pg/ml）时，GFR的降低程度低于RBF。这种现象也可以观察到较低的血浆A II浓度（平均200 pg/ml），当肾素-血管紧张素系统已预先适度激活。
The effects of a 60-min intravenous infusion of angiotensin II (A II; 4 or 20 ng A II/min/kg body weight) on renal blood flow (RBF; electromagnetic flow transducer, control value 19-25 ml/min/kg), glomerular filtration rate (GFR; control value 4.2-5.0 ml/min/kg), mean arterial blood pressure, sodium excretion, water excretion, and plasma A II and plasma aldosterone concentrations were examined in 6 chronically instrumented female conscious beagle dogs kept on three different dietary sodium intakes (SI): SI 0.5 or SI 2.5 mmol Na/kg/day or SI 4.5 mmol Na/kg/day plus an oral saline load prior to the experiment SI 4.5(+) dogs. Four nanograms A II decreased RBF and GFR in SI 4.5(+) dogs without changing the filtration fraction (FF%); in SI 0.5 dogs the RBF decreased, and the FF% increased. Twenty nanograms A II decreased RBF and increased FF% in all dietary protocols, less in SI 4.5(+) dogs. The mean arterial blood pressure increased in all dietary protocols by 10-15 mm Hg (4 ng A II) and 32-37 mm Hg (20 ng A II). Sodium and water excretions decreased by 32 and 46%, respectively, in SI 4.5(+) dogs at both doses of A II. The plasma aldosterone concentration increased in all but one protocol: 4 ng A II, SI 4.5(+) dogs. It is concluded that when A II plasma concentrations are most likely borderline to pathophysiological conditions (up to an average of 370 pg/ml), the GFR is less decreased than the RBF. This phenomenon also can be observed at lower plasma A II concentrations (average 200 pg/ml), when the renin-angiotensin system had been previously moderately activated.