Melaragno M G, Fink G D
Department of Pharmacology and Toxicology, Michigan State University, East Lansing 48824.
Hypertension. 1995 Feb;25(2):288-93. doi: 10.1161/01.hyp.25.2.288.
Phase II of two-kidney, one clip (2K1C) Goldblatt hypertension in the rat is characterized by elevated blood pressure and near-normal plasma concentrations of angiotensin II (Ang II) but is reversed by inhibition of the renin-angiotensin system. We hypothesized that this angiotensin dependence is due to enhanced responsiveness to the slow pressor effect of Ang II caused by renal artery stenosis. To test this idea, we submitted rats to either renal artery clipping or sham operation. These groups were immediately subdivided; some animals received enalapril in their drinking water (508 mumol/L), and the rest drank distilled water only. After 10 to 14 days, catheters were inserted into the aorta and vena cava, and the rats were housed in metabolism cages. After 3 control days of measurement of mean arterial pressure and other variables, the enalapril-treated groups received an intravenous infusion of Ang II at a dose of 3.8 pmol/min (4 ng/min) for 14 days. Rats not drinking enalapril received only saline vehicle (2 mmol Na+ per day). After 3 days of Ang II infusion, the enalapril-treated 2K1C rats had attained a significantly higher level of mean arterial pressure than the enalapril-treated sham rats. At the end of the Ang II infusion, mean arterial pressure in enalapril-treated 2K1C rats was 151 +/- 6 mm Hg versus 107 +/- 7 mm Hg in enalapril-treated sham rats. Mean arterial pressure in the enalapril-treated sham rats after Ang II infusion was not significantly different from that of untreated sham rats (109 +/- 2 mm Hg).(ABSTRACT TRUNCATED AT 250 WORDS)
大鼠双肾单夹（2K1C）型Goldblatt高血压的第二阶段表现为血压升高，而血浆血管紧张素II（Ang II）浓度接近正常，但肾素-血管紧张素系统受抑制后血压可恢复正常。我们推测这种对血管紧张素的依赖性是由于肾动脉狭窄导致对Ang II缓慢升压作用的反应性增强所致。为验证这一观点，我们将大鼠进行肾动脉夹闭或假手术。这些组随即再细分；部分动物饮用含依那普利（508 μmol/L）的水，其余仅饮用蒸馏水。10至14天后，将导管插入主动脉和腔静脉，大鼠饲养于代谢笼中。在测量平均动脉压和其他变量的3天对照期后，接受依那普利治疗的组以3.8 pmol/分钟（4 ng/分钟）的剂量静脉输注Ang II，持续14天。未饮用依那普利的大鼠仅接受生理盐水载体（每天2 mmol Na+）。输注Ang II 3天后，接受依那普利治疗的2K1C大鼠的平均动脉压水平显著高于接受依那普利治疗的假手术大鼠。在Ang II输注结束时，接受依那普利治疗的2K1C大鼠的平均动脉压为151±6 mmHg，而接受依那普利治疗的假手术大鼠为107±7 mmHg。Ang II输注后，接受依那普利治疗的假手术大鼠的平均动脉压与未治疗的假手术大鼠（109±2 mmHg）无显著差异。（摘要截短于250字）
