Effect of nitric oxide on single skeletal muscle fibres from the mouse
Effect of nitric oxide on single skeletal muscle fibres from the mouse
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DOI：
10.1111/j.1469-7793.1998.577bn.x
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发表时间：
1998-06-01
影响因子：
5.5
通讯作者：
Westerblad, H
中科院分区：
文献类型：
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作者：
Andrade, FH;Reid, MB;Westerblad, H
1.以小鼠足肌为材料，研究一氧化氮对骨骼肌收缩功能的影响.我们测量了一氧化氮供体S-亚硝基-N-乙酰半胱氨酸（SNAC）和硝普钠作用下单纤维的力产生和肌浆游离钙浓度（[Ca 2 +]（i））.一氧化氮供体降低肌原纤维Ca 2+敏感性，而[Ca 2 +]（i）瞬变增加在亚最大强直。力量基本上没有变化。SNAC没有改变最大缩短速度、力再发展速率或饱和[Ca 2 +]时的力产生（i）。鸟苷酸环化酶抑制剂LY 83583增加强直性[Ca 2 +]（i），但对Ca 2+敏感性没有影响。LY 83583不能阻止SNAC引起的肌原纤维Ca 2+敏感性降低。氧化剂亚硝酸钠可增加强直性[Ca 2 +]（i），降低肌原纤维Ca 2+敏感性.我们的结论是，在我们的实验条件下，一氧化氮损害Ca 2+激活的肌动蛋白丝，导致肌原纤维Ca 2+敏感性降低。
1. Single skeletal muscle fibres from a mouse foot muscle were used to investigate the effects of nitric oxide on contractile function.2. We measured force production and myoplasmic free Ca2+ concentration ([Ca2+](i)) in single fibres exposed to the nitric oxide donors S-nitroso-N-acetylcysteine (SNAC) and nitroprusside.3. The nitric oxide donors reduced myofibrillar Ca2+ sensitivity whereas [Ca2+](i) transients were increased during submaximal tetani. Force was largely unchanged. SNAC did not change maximum shortening velocity, the rate of force redevelopment, or force production at saturating [Ca2+](i).4. The guanylyl cyclase inhibitor LY83583 increased tetanic [Ca2+](i) but had no effect on Ca2+ sensitivity. LY83583 did not prevent the decrease in myofibrillar Ca2+ sensitivity in response to SNAC. The oxidizer sodium nitrite increased tetanic [Ca2+](i) and decreased myofibrillar Ca2+ sensitivity.5. We conclude that under our experimental conditions nitric oxide impairs Ca2+ activation of the actin filaments which results in decreased myofibrillar Ca2+ sensitivity.