Cardona-Sanclemente L E, Medina R, Born G V
Pathopharmacology Unit, William Harvey Research Institute, St. Bartholomew's Hospital Medical College, London, United Kingdom.
Proc Natl Acad Sci U S A. 1994 Apr 12;91(8):3285-8. doi: 10.1073/pnas.91.8.3285.
The effect of 6 days' s.c. infusions of angiotensin II at increasing doses was determined on the uptake of rat or human low density lipoprotein (LDL) and of human fibrinogen by aorta in normal and spontaneously hypertensive rats. Rat or human LDL or human fibrinogen was injected i.v. 5 days after the start of infusion, and 24 hr later the radioactivity of aortic walls was determined. Body weight was almost constant in control rats and moderately decreased in a dose-dependent way by angiotensin II. Diastolic blood pressure decreased slightly over 6 days in control rats and increased transiently at the lowest dose of angiotensin II and progressively with two higher concentrations. All three angiotensin II concentrations significantly increased the uptake of rat and human LDL and of fibrinogen by aorta. The increase was dose related for rat LDL but not for human LDL or fibrinogen. In spontaneously hypertensive rats of the same age in which blood pressure was higher than in angiotensin II-infused rats, protein uptakes were not increased. The blood content of aortic walls was negligible and not altered by angiotensin II. Therefore, the uptake of atherogenic plasma proteins by rat aorta is increased by angiotensin II, but this effect may be independent of its pressor action.
研究了在正常大鼠和自发性高血压大鼠中，连续6天皮下注射递增剂量的血管紧张素II对主动脉摄取大鼠或人低密度脂蛋白（LDL）以及人纤维蛋白原的影响。在开始输注血管紧张素II 5天后静脉注射大鼠或人LDL或人纤维蛋白原，24小时后测定主动脉壁的放射性。对照大鼠体重几乎保持恒定，血管紧张素II使其体重呈剂量依赖性适度下降。对照大鼠的舒张压在6天内略有下降，在血管紧张素II最低剂量时短暂升高，并随两个较高浓度逐渐升高。所有三个血管紧张素II浓度均显著增加主动脉对大鼠和人LDL以及纤维蛋白原的摄取。这种增加与大鼠LDL的剂量相关，但与人LDL或纤维蛋白原无关。在相同年龄的自发性高血压大鼠中，其血压高于输注血管紧张素II的大鼠，蛋白质摄取并未增加。主动脉壁的血液含量可忽略不计，且不受血管紧张素II的影响。因此，血管紧张素II可增加大鼠主动脉对致动脉粥样硬化血浆蛋白的摄取，但这种作用可能与其升压作用无关。
