Protein expression, vascular reactivity and soluble guanylate cyclase activity in mice lacking the endothelial cell nitric oxide synthase: contributions of NOS isoforms to blood pressure and heart rate control
Protein expression, vascular reactivity and soluble guanylate cyclase activity in mice lacking the endothelial cell nitric oxide synthase: contributions of NOS isoforms to blood pressure and heart rate control
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DOI：
10.1016/s0008-6363(98)00315-0
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发表时间：
1999-04-01
影响因子：
10.8
通讯作者：
Harrison, DG
中科院分区：
文献类型：
--
作者：
Kojda, G;Laursen, JB;Harrison, DG
目的：内皮型一氧化氮合酶(ENOS)基因突变和药物抑制均可导致轻度高血压。目前尚不清楚eNOS以外的其他NOS亚型是否以及在多大程度上参与了这一效应，以及eNOS基因一个副本的丢失可能如何影响血管反应性或eNOS蛋白的表达。方法：检测eNOS基因完全缺失小鼠(eNOS(-/-))、野生型小鼠(eNOS(+/+))和eNOS杂合子小鼠(eNOS(+/-))的蛋白表达、血管反应性、可溶性鸟苷环化酶活性、血压和心率。结果：eNOS(-/-)小鼠有轻度高血压和心动过缓，eNOS(+/-)小鼠血压正常。在对照组小鼠中，口服L-NAME(约100 mg/kg/天×21天)可使血压升高至eNOS(-/-)小鼠观察到的水平。在eNOS(-/-)小鼠中，长期口服L-NAME对血压没有影响，这表明抑制其他一氧化氮合酶亚型不太可能导致高血压。L-NAME治疗引起对照组和eNOS(-/-)小鼠心动过缓，提示eNOS和其他亚型的一氧化氮合酶都可能参与心率控制。对eNOS(-/-)小鼠的主动脉环的研究显示，对乙酰胆碱和钙离子载体A23187的反应完全缺乏内皮依赖的血管松弛，而对苯肾上腺素、5-羟色胺和硝酸甘油的敏感性增加。与eNOS(+/+)小鼠的血管相比，eNOS(+/-)小鼠的主动脉环对硝酸甘油的反应仅有轻微的变化，对乙酰胆碱或A23187的反应正常。Western分析显示eNOS(+/+)和eNOS(+/-)小鼠的eNOS表达基本相同，而eNOS(-/-)小鼠则不表达。三种品系小鼠肺分离的可溶性鸟苷环化酶活力相同。结论：我们得出结论，在杂合子动物中观察到的eNOS基因的一个拷贝的丢失对血管反应性、血压或eNOS蛋白的表达没有影响。一氧化氮合酶的亚型，而不是eNOS，不太可能参与血压调节，但可能参与心率控制。(C)1999年爱思唯尔科学公司。版权所有。
Objective: Both disruption of the endothelial nitric oxide synthase (eNOS) gene and pharmacological inhibition of the NOS produce modest hypertension. It is unclear if and to what extent NOS isoforms other than eNOS contribute to this effect and how loss of one copy of the eNOS gene might impact on vascular reactivity or eNOS protein expression. Methods: We examined protein expression, vascular reactivity, activity of soluble guanylate cyclase, blood pressure and heart rate in mice completely lacking the eNOS gene (eNOS(-/-)), wild-type mice (eNOS(+/+)) and mice heterozygotic for the eNOS gene (eNOS(+/-)). Results: While eNOS(-/-) mice had mild hypertension and bradycardia, eNOS(+/-) mice were normotensive. In control mice, oral administration of L-NAME (approximately 100 mg/kg/day x21 days) increased blood pressure to levels observed in eNOS(-/-) mice. In eNOS(-/-) mice, chronic oral administration of L-NAME had no effect on blood pressure, suggesting that inhibition of other NOS isoforms unlikely contribute to hypertension. L-NAME treatment induced bradycardia in both control and eNOS(-/-) mice, suggesting that both eNOS and other isoforms of NOS might be involved in heart rate control. Studies of aortic rings from eNOS(-/-) mice revealed a complete lack of endothelium-dependent vascular relaxation in response to acetylcholine and the calcium ionophore A23187 and an increase in sensitivity to phenylephrine, serotonin and nitroglycerin. Aortic rings from eNOS(+/-) mice demonstrated only minor alterations of responses to nitroglycerin and a normal relaxation to either acetylcholine or A23187 compared to vessels from eNOS(+/+). Western analysis demonstrated that eNOS expression was virtually identical between eNOS(+/+) and eNOS(+/-) mice and was absent in eNOS(-/-) mice. The activity of lung-isolated soluble guanylate cyclase was identical in the three strains of mice. Conclusions: We conclude that loss of one copy of the eNOS gene, as observed in heterozygotic animals, has no effect on vascular reactivity, blood pressure or eNOS protein expression. Isoforms of NOS, other than eNOS are unlikely involved in blood pressure regulation but may participate in heart rate control. (C) 1999 Elsevier Science BN. All rights reserved.