诱导型一氧化氮合酶与Dahl-盐敏感大鼠动脉血压的调节

目的和方法:为探讨诱导型一氧化氮合酶 (iNOS)在血液动力学调控中的作用,本研究通过慢性血液动力学实验观察了静脉输入诱导型一氧化氮合酶 (iNOS)抑制剂aminogunidine(AG)对大鼠平均动脉压的影响,并测定了一氧化氮 (NO)终产物NO₂及NO₃含量(UNOx)以及iNOS活性。结果:1.iNOS特异抑制剂AG能明显放大高钠引起的Dahl盐敏感大鼠(DS)的血压上升效应;2.高NaCl输入在导致的DS大鼠血压升高的同时,能引起iNOS活性及UNOx的明显升高。结论:iNOS对DS大鼠具有重要的血液动力学调节作用。

The role of inducible nitric oxide synthase in the regulation of arterial pressure in Dahl salt-sensitive rats

AIM AND METHODS: To clarify the role of inducible nitric oxide synthase (iNOS) in the hemodynamic regulation of Dahl salt-sensitive (DS) rats,in the present study, we examined the effect of aminoguanidine (AG), a selective inhibitor of iNOS on the pressor response of DS rats to high sodium chloride (NaCl) intake by chronical in vivo hemodynamic experiment, and the effect of NaCl or NaCl plus AG infusion on urinary nitrate (NO- 3)/nitrite (NO- 2), the end product of nitric oxide (NO), excretion by Greiss Reaction. Furthermore, an iNOS activity assay was also made. RESULTS: The hypertensive effect of high NaCl (8%) infusion was greatly amplified by co-infusion of AG. Administration of high NaCl significantly elevated the iNOS activity of renal tissue including cortex, inner medulla and outer medulla, and greatly increased urinary NO- 3/NO- 2 excretion. CONCLUSION: Inducible NOS is an important modulator of blood pressure in DS rats under the condition of NaCl-induced hypertension.