Reduced oxidative phosphorylation and proton efflux suggest reduced capillary blood supply in skeletal muscle of patients with dermatomyositis and polymyositis:: a quantitative 31P-magnetic resonance spectroscopy and MRI study
Reduced oxidative phosphorylation and proton efflux suggest reduced capillary blood supply in skeletal muscle of patients with dermatomyositis and polymyositis:: a quantitative 31P-magnetic resonance spectroscopy and MRI study
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DOI：
10.1093/brain/awf163
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发表时间：
2002-07-01
期刊：
影响因子：
14.5
通讯作者：
Taylor, DJ
中科院分区：
文献类型：
--
作者：
Cea, G;Bendahan, D;Taylor, DJ
采用定量MRI和磷磁共振波谱（P-31-MRS）技术对皮肌炎（DM）和多发性肌炎（PM）患者体内骨骼肌代谢进行研究，探讨线粒体异常在皮肌炎发病机制和临床表现中的作用。9例DM患者（平均年龄+/- SD， 57 +/- 14岁）和5例PM患者（42 +/- 12岁），发病年龄分别为53 +/- 16岁和38 +/- 12岁，与18例年龄匹配的对照组一起纳入研究。DM和PM组运动后肌肉氧化代谢P-31-MRS指标均受损。在两组患者中，磷酸肌酸和二磷酸腺苷恢复一半的时间几乎是对照组的两倍（每个变量P < 0.05），线粒体ATP产生的最大速率是正常受试者的一半（P < 0.001）。DM （P < 0.001）和PM （P = 0.02）的肌纤维质子流出率显著降低。DM和PM患者的P-31-MRS恢复指数的损害与一组10例质子流出率正常的原发性线粒体疾病患者相似。磁共振成像检测到的异常与炎症程度或肌肉脂肪浸润之间没有相关性。DM和PM患者的体内研究结果表明肌肉有氧功能受损，考虑到质子外排减少，这可能是继发于血液供应受损。我们的结果表明，在一些肌肉活检中看到的异常线粒体不太可能是这些患者氧化功能不全的主要原因。
Quantitative MRI and phosphorus magnetic resonance spectroscopy (P-31-MRS) were used to investigate skeletal muscle metabolism in vivo in patients with dermatomyositis (DM) and polymyositis (PM) in order to evaluate the role of mitochondrial abnormalities in the pathogenesis and clinical expression of these conditions. Nine patients with DM (mean age +/- SD, 57 +/- 14 years) and five with PM (42 +/- 12 years) and with age at disease onset 53 +/- 16 and 38 +/- 12 years, respectively, were included in the study together with 18 age-matched controls. Post-exercise P-31-MRS indices of muscle oxidative metabolism were all impaired in DM and PM. In both groups of patients, the phosphocreatine and adenosine diphosphate recovery half-times were almost twice as long as in controls (P < 0.05 for each variable) and the maximum rate of mitochondrial ATP production was half that found in normal subjects (P < 0.001). The rate of proton efflux from muscle fibres was significantly reduced in DM (P < 0.001) and PM (P = 0.02). The impairment of P-31-MRS recovery indices in DM and PM patients was similar to that found in a group of 10 patients with a primary mitochondrial disorder that showed a normal proton efflux rate. There was no correlation between the MRS-detectable abnormalities and the degree of inflammation or fatty infiltration of the muscle, as measured by MRI. The in vivo findings in DM and PM patients indicate impaired muscle aerobic function, which, considering the reduced proton efflux, is likely to be secondary to an impaired blood supply. Our results suggest that the abnormal mitochondria seen in some muscle biopsies are unlikely to be the primary cause of the oxidative insufficiency in these patients.