心血管组织钙化大鼠心肌肌浆网一氧化氮合酶的改变

目的:观察心血管组织钙化大鼠心肌肌浆网一氧化氮合酶/一氧化氮系统的改变,以探讨是否SR上NO的过量生成是钙化心肌SR功能抑制的重要机制。方法:维生素D3肌肉注射和nicotine灌胃复制大鼠心血管组织钙化的模型。差速离心制备心肌肌浆网,检测SR中NO生成及NOS的活性和蛋白表达。结果:心血管组织钙化处理6周大鼠心肌钙含量比对照组高4倍(P＜0.01),钙化组心肌SR的NO产生高于对照组,NOS活性增加,NOS蛋白表达比对照组高54%(P＜0.01)。钙化处理2周左右尽管心肌钙化尚不明显,但SR的NOS/NO系统已经发生改变。结论:心血管组织钙化大鼠心肌SR的NOS/NO系统的上调,是钙化心肌SR功能抑制的重要机制之一。

Alterations of nitric oxide synthase in cardiac sarcoplasmic reticulum from rats with myocardial calcification

AIM: To study alterations of nitric oxide synthase (NOS) in cardiac sarcop lasmic reticulum from rats with myocardial calcification, and to explore the mec hanism of inhibition of SR function in the rats with myocardial calcification. METHODS: The myocardial calcification rat models were prepared by vit amin D3 plus nicotine for 2 weeks and 6 weeks. Cardiac SR was separated by centrifugating. T he nitric oxide (NO) production, NOS activity and NOS protein expression in the SR were perfor med. RESULTS: Compared with control, myocardial calcium content in t he 6 weeks i ncreased by 408%(P<0 01), the NO production, NOS activity and NOS pro tein expression in the SR with myocardial calcification increased versus control( P< 0 01).Myocardial calcium content was not alterations significantly, but the NO S /NO pathway in the SR was up-regulated slightly in the 2 weeks. CONCLUSION : The up-regulated NOS/NO system in the SR with myocardial calcification is the impor tant mechanism of function inhibition of the SR.