Vascular wall energetics in arterioles during nitric oxide-dependent and -independent vasodilation
Vascular wall energetics in arterioles during nitric oxide-dependent and -independent vasodilation
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DOI：
10.1152/japplphysiol.01632.2005
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发表时间：
2006-06-01
影响因子：
3.3
通讯作者：
Kamiya, Akira
中科院分区：
文献类型：
--
作者：
Shibata, Masahiro;Qin, Kairong;Kamiya, Akira
本研究的目的是评估血管内皮细胞释放的一氧化氮（NO）是否会通过减少血管平滑肌机械功的能量消耗来减少血管壁的耗氧量。在大鼠提睾肌的小动脉壁的耗氧率测定在体内NO依赖性和非依赖性血管舒张的基础上的血管内和血管周围的氧张力（PO2）通过磷光猝灭激光显微镜测量。NO依赖性血管舒张是由于血流量增加导致的NO产生增加而引起的，而NO非依赖性血管舒张是由局部施用罂粟碱引起的。血管壁的能量效率通过在正常和血管舒张条件之间的小动脉中的周向壁应力（机械功的量）与血管壁耗氧率（能量成本）的可变比率来评价。NO依赖性和非依赖性扩张分别增加了13%和17%的小动脉直径，相对于正常条件下的值。NO依赖性和非依赖性血管舒张时血管壁耗氧量均较正常时显著降低。然而，在NO非依赖性血管舒张过程中的血管壁耗氧量显着低于NO依赖性血管舒张过程中。另一方面，在NO依赖性和非依赖性血管舒张过程中血管壁的能量效率之间没有显著差异，这表明NO产生的血管壁耗氧量的降低与血管平滑肌机械功的降低有关。
The objective of this study was to evaluate whether the nitric oxide ( NO) released from vascular endothelial cells would decrease vessel wall oxygen consumption by decreasing the energy expenditure of mechanical work by vascular smooth muscle. The oxygen consumption rate of arteriolar walls in rat cremaster muscle was determined in vivo during NO-dependent and -independent vasodilation on the basis of the intra- and perivascular oxygen tension (PO2) measured by phosphorescence quenching laser microscopy. NO-dependent vasodilation was induced by increased NO production due to increased blood flow, whereas NO-independent vasodilation was induced by topical administration of papaverine. The energy efficiency of vessel walls was evaluated by the variable ratio of circumferential wall stress (amount of mechanical work) to vessel wall oxygen consumption rate (energy cost) in the arteriole between normal and vasodilated conditions. NO-dependent and -independent dilation increased arteriolar diameters by 13 and 17%, respectively, relative to the values under normal condition. Vessel wall oxygen consumption decreased significantly during both NO-dependent and -independent vasodilation compared with that under normal condition. However, vessel wall oxygen consumption during NO-independent vasodilation was significantly lower than that during NO-dependent vasodilation. On the other hand, there was no significant difference between the energy efficiency of vessel walls during NO-dependent and -independent vasodilation, suggesting the decrease in vessel wall oxygen consumption produced by NO to be related to reduced mechanical work of vascular smooth muscle.