Chati Z, Michel C, Escanye J M, Mertes P M, Ribuot C, Canet D, Zannad F
Department of Cardiology and Pharmacology, University of Henri Poincaré, Nancy, France.
Am J Physiol. 1996 Nov;271(5 Pt 2):H1739-45. doi: 10.1152/ajpheart.1996.271.5.H1739.
To investigate the mechanisms leading to skeletal muscle metabolic abnormalities in chronic heart failure (CHF), we studied phosphate metabolism and skeletal muscle beta-adrenoreceptors (beta-AR) in rats 12-14 wk after coronary ligation (CL). We performed 31P magnetic resonance spectroscopy in the gastrocnemius muscle during motor activity produced by electrical stimulation (5 Hz). The initial slope of phosphocreatine (PCr) depletion was higher in the CL rats compared with sham-operated rats (Pi/PCr/time: 0.211 +/- 0.045 vs. 0.113 +/- 0.029; P < 0.05). During recovery, both PCr resynthesis rate and maximal rate of oxidative ATP synthesis were reduced threefold in the CL rats compared with controls (11 +/- 2 vs. 37 +/- 7 mmol.l-1.min-1, P < 0.04; and 20 +/- 3 vs. 79 +/- 18 mmol.l-1.min-1, P < 0.03, respectively). There were no significant differences either for the skeletal muscle density (13 +/- 6 vs. 15 +/- 3 fM/mg) or for the affinity (0.244 +/- 0.149 vs. 0.246 +/- 0.146 nM) of beta-AR between the two groups. This study showed that, although in moderate CHF skeletal muscle metabolic abnormalities can be demonstrated, these changes could not be explained by skeletal muscle beta-adrenergic receptor alterations in this experimental model.
为研究慢性心力衰竭（CHF）导致骨骼肌代谢异常的机制，我们在冠状动脉结扎（CL）后12 - 14周的大鼠中研究了磷酸盐代谢和骨骼肌β - 肾上腺素能受体（β - AR）。我们在电刺激（5Hz）产生的运动活动期间，对腓肠肌进行了31P磁共振波谱分析。与假手术大鼠相比，CL大鼠中磷酸肌酸（PCr）消耗的初始斜率更高（Pi/PCr/时间：0.211±0.045 vs. 0.113±0.029；P < 0.05）。在恢复过程中，与对照组相比，CL大鼠的PCr再合成率和氧化ATP合成的最大速率均降低了三倍（分别为11±2 vs. 37±7 mmol·l-1·min-1，P < 0.04；以及20±3 vs. 79±18 mmol·l-1·min-1，P < 0.03）。两组之间骨骼肌密度（13±6 vs. 15±3 fM/mg）或β - AR的亲和力（0.244±0.149 vs. 0.246±0.146 nM）均无显著差异。本研究表明，虽然在中度CHF中可证明骨骼肌代谢异常，但在该实验模型中，这些变化无法用骨骼肌β - 肾上腺素能受体改变来解释。
