Bekedam Martijn A, van Beek-Harmsen Brechje J, van Mechelen Willem, Boonstra Anco, Visser Frans C, van der Laarse Willem J
Department of Cardiology, Institute for Cardiovascular Research, VU University medical center, Amsterdam, The Netherlands.
Int J Cardiol. 2009 Apr 3;133(2):185-90. doi: 10.1016/j.ijcard.2007.12.025. Epub 2008 Feb 14.
Reduced exercise tolerance and muscle weakness are present in patients with CHF. Altered metabolism, histology and function in skeletal muscle of patients with CHF have been reported. The sarcoplasmic reticulum (SR) has control of Ca(++) release and uptake required for contraction and relaxation, respectively, and uses a considerable amount of energy. Little is known about SR alterations in CHF. We determined sarcoplasmic reticulum adenosine triphosphatase (SR ATPase) activity in different types of skeletal muscle fibres of CHF patients.
SR ATPase activity, succinate dehydrogenase (SDH) activity and myofibrillar adenosine triphosphatase (M ATPase) activity in single fibres of the vastus lateralis muscle in 16 CHF patients and 5 controls was determined using quantitative enzyme histochemistry.
SR ATPase activity of type II skeletal muscle fibers was significantly higher compared to type I fibres. SR ATPase activity in type II skeletal muscle fibres of CHF patients was higher than in control subjects.
Increased skeletal muscle SR ATPase activity contributes to reduced exercise tolerance in CHF patients.
慢性心力衰竭（CHF）患者存在运动耐力下降和肌肉无力的情况。已有报道称CHF患者骨骼肌的代谢、组织学和功能发生改变。肌浆网（SR）分别控制着收缩和舒张所需的钙离子（Ca++）释放和摄取，且消耗大量能量。关于CHF中肌浆网的改变知之甚少。我们测定了CHF患者不同类型骨骼肌纤维中的肌浆网三磷酸腺苷酶（SR ATPase）活性。
采用定量酶组织化学法测定16例CHF患者和5例对照者股外侧肌单纤维中的SR ATPase活性、琥珀酸脱氢酶（SDH）活性和肌原纤维三磷酸腺苷酶（M ATPase）活性。
II型骨骼肌纤维的SR ATPase活性显著高于I型纤维。CHF患者II型骨骼肌纤维中的SR ATPase活性高于对照组。
骨骼肌SR ATPase活性增加导致CHF患者运动耐力下降。
