Schaufelberger M, Drexler H, Schieffer E, Swedberg K
Department of Medicine, Sahlgrenska University Hospital/Ostra, Göteborg University, Sweden.
J Card Fail. 1998 Sep;4(3):185-91. doi: 10.1016/s1071-9164(98)80005-5.
Skeletal muscle factors may influence functional limitation in patients with heart failure. The renin-angiotensin system is activated in chronic heart failure. Treatment with angiotensin-converting enzyme (ACE) inhibitors improve symptoms and prognosis. The goal of this study was to quantify and localize skeletal muscle ACE-mRNA in patients with chronic heart failure and in control subjects, and to elucidate skeletal muscle fiber area and capillary density.
Biopsies from the lateral vastus muscle were taken from 9 patients before and after treatment with enalapril and in 10 control subjects. ACE-mRNA was quantified with reverse transcription polymerase chain reaction. Immunohistochemistry was used to localize ACE within skeletal muscle. No difference in ACE-mRNA transcripts between patients and control subjects was detected, nor did ACE gene expression change after treatment with enalapril. The number of ACE-mRNA transcripts was related to muscle fiber area, whereas an inverse relationship between the number of ACE transcripts and capillary density was found. ACE was detected in the endothelial cells of capillaries in skeletal muscle.
ACE is expressed in skeletal muscle and is confined to endothelial cells. The close relationship between capillary density and number of ACE transcripts indicate that activation of the renin-angiotensin system has an impact on capillary growth.
骨骼肌因子可能影响心力衰竭患者的功能受限情况。肾素-血管紧张素系统在慢性心力衰竭中被激活。使用血管紧张素转换酶（ACE）抑制剂进行治疗可改善症状并改善预后。本研究的目的是对慢性心力衰竭患者和对照受试者的骨骼肌ACE-mRNA进行定量和定位，并阐明骨骼肌纤维面积和毛细血管密度。
从9例接受依那普利治疗前后的患者以及10例对照受试者的股外侧肌获取活检样本。采用逆转录聚合酶链反应对ACE-mRNA进行定量。免疫组织化学用于在骨骼肌中定位ACE。未检测到患者与对照受试者之间ACE-mRNA转录本存在差异，依那普利治疗后ACE基因表达也未发生变化。ACE-mRNA转录本的数量与肌纤维面积相关，而ACE转录本数量与毛细血管密度之间呈负相关。在骨骼肌毛细血管的内皮细胞中检测到了ACE。
ACE在骨骼肌中表达，且局限于内皮细胞。毛细血管密度与ACE转录本数量之间的密切关系表明肾素-血管紧张素系统的激活对毛细血管生长有影响。
