缺氧对豚鼠主动脉中血管紧张素Ⅱ含量和受体的影响(英文)

Effect of hypoxia on angiotensin I content and its receptor in guinea pig aorta

目的:观察缺氧对血管紧张素Ⅱ(angiotensinⅡ,AngⅡ)收缩血管,AngⅡ含量及受体的影响.方法:冲氮气诱导离体豚鼠主动脉缺氧记录加AngⅡ后,主动脉的收缩变化.放射免疫方法测定AngⅡ含量,并进行受体结合实验.结果:AngⅡ3—3000 nmol L^(-1)加强主动脉收缩.缺氧明显加强AngⅡ的血管收缩作用,缺氧和不缺氧主动脉中AngⅡ含量分别为50±17和44±24(pg/g wet wt,n=10),而受体密度则明显不同,前者为33±5,后者17±3fmol mg^(-1).结论:缺氧加强AngⅡ的血管收缩作用与血管紧张素受体有关.

To study the effects of hypoxia on the vasoconstrictive response and the angiotensin Ⅱ( Ang Ⅱ) content and its receptor. METHODS: Hypoxia was induced in isolated aorta of guinea pig by gassing N2. The vasoconstrictive response of aorta to Ang Ⅱ was recorded. Ang I content and its receptor were measured by radioimmuoassay. RESULTS: Ang 3 - 3000 nmol L^1 increased the contractile response of aorta. Hypoxia amplified the vasoconstrictve effect of Ang Ⅱ. The concentration of Ang I were 44 ± 24 and 50±17 pg/g wet wt (n=10), respectively in non-hypoxic and hypoxic aortae. The receptor density in non-hypoxic aorta was 17 ±3 fmol mg-1, and that in hypoxia was 33 ± 5 fmol mg-1(P<0. 01). CONCLUSION: The enhancement of the vasoconstrictive action of Ang I by hypoxia is due to the increase in the angiotensin receptor density, but not associated with the changes in the Ang Ⅱ content in hypoxic aorta of guinea pig.