Modulation of in vivo cardiac function by myocyte-specific nitric oxide synthase-3
Modulation of in vivo cardiac function by myocyte-specific nitric oxide synthase-3
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DOI：
10.1161/01.res.0000119323.79644.20
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发表时间：
2004-03-19
影响因子：
20.1
通讯作者：
Kass, DA
中科院分区：
文献类型：
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作者：
Champion, HC;Georgakopoulos, D;Kass, DA
一氧化氮(NO)主要作为扩散性旁分泌效应器发挥作用。心肌细胞是个例外，在那里没有合成酶(NOS)和靶蛋白共存，允许NO以自分泌/内分泌的方式工作。然而，最丰富的肌细胞亚型(NOS3)在血管内皮细胞中表达更多；因此，肌细胞-NOS3在体内的作用尚不清楚。本研究通过将表达NOS3的腺病毒与α-MHC启动子偶联(ADV(NOS3))导入NOS3缺失(NOS3(-/-))小鼠的整个心脏，并将结果与感染标记基因β-半乳糖苷酶(ADVβ-Galactosidase，GAL)的心脏进行比较，以检验这一作用。NOS3(-/-)+Adv(NOS3)组心肌总NOS3蛋白和活性恢复到接近野生型(WT)水平，NOS3在小窝蛋白-3作用下重新定位正常。压力-容量分析显示，与WT或NOS3(-/-)+Adv(NOS3)相比，NOS3(-/-)+AdVbeta(GAL)组的射血功能增强。更显著的是，NOS3(-/-)+AdVbeta(GAL)组WT的异丙肾上腺素(ISO)刺激的收缩和舒张期功能被放大，而NOS3(-/-)+ADV(NOS3)组的反应恢复到对照组。在NOS3(-/-)+ADV(NOS3)的心脏上，同时给予M胆碱(卡巴胆碱)可抑制85%的等激活收缩功能，但不能抑制NOS3(-/-)+AdVbeta(GAL)的收缩功能。最后，NOS3(-/-)+AdVbeta(GAL)组小鼠在较慢的心率下表现出比WT更强的肌力和肌力，但与对照组相比心率增加迟钝。NOS3(-/-)+ADV(NOS3)的阳性反应恢复(P<；0.001)。因此，体内心肌细胞自分泌/内分泌NOS3的调节可能在β肾上腺素能、毒鼠碱和频率依赖性心脏调节中起关键作用。
Nitric oxide ( NO) functions principally as a diffusible paracrine effector. The exception is in cardiomyocytes where both NO synthases ( NOS) and target proteins coexist, allowing NO to work in an autocrine/ intracrine fashion. However, the most abundant myocyte isoform ( NOS3) is far more expressed in vascular endothelium; thus, the in vivo contribution of myocyte- NOS3 remains less clear. The present study tested this role by transfecting whole hearts of NOS3- null ( NOS3(-/-)) mice with adenovirus- expressing NOS3 coupled to alpha-MHC promoter ( AdV(NOS3)), comparing results to hearts transfected with marker-gene beta-galactosidase ( AdV beta(gal)). Total myocardial NOS3 protein and activity were restored to near wild- type ( WT) levels in NOS3(-/-) +AdV(NOS3) hearts, and NOS3 relocalized normally with caveolin- 3. Ejection function by pressure- volume analysis was enhanced in NOS3(-/-) +AdVbeta(gal) over WT or NOS3(-/-) +AdV(NOS3). More prominently, isoproterenol ( ISO)- stimulated systolic and diastolic function in WT was amplified in NOS3(-/-) +AdVbeta(gal), whereas NOS3(-/-) +AdV(NOS3) returned the response to control. ISO- activated systolic function was inhibited 85% by concomitant muscarinic stimulation ( carbachol) in NOS3(-/-) +AdV(NOS3) but not NOS3(-/-) +AdVbeta(gal) hearts. Lastly, NOS3(-/-) +AdVbeta(gal) mice displayed enhanced inotropy and lusitropy over WT at slower heart rates but a blunted rate augmentation versus controls. A more positive rate response was restored in NOS3(-/-) +AdV(NOS3) ( P < 0.001). Thus, myocyte autocrine/ intracrine NOS3 regulation in vivo can underlie key roles in beta- adrenergic, muscarinic, and frequency- dependent cardiac regulation.