Tikunov B A, Mancini D, Levine S
Pulmonary and Critical Care Section, VA Medical Center, Philadelphia, PA, USA.
J Mol Cell Cardiol. 1996 Dec;28(12):2537-41. doi: 10.1006/jmcc.1996.0245.
We describe the changes in proportions of myofibrillar proteins elicited by chronic congestive heart failure in the costal diaphragm (DIA) of humans using one and two-dimensional electrophoretic techniques. Three myosin heavy chain (MHC) isoforms were found in the DIA from control subjects: slow MHC I (43 +/- S.E. 2%), fast MHC IIa (41 +/- 2%) and fast MHC IIb (17 +/- 1%). In heart failure DIA, the percentage of MHC I was increased to 57 +/- 2%, while that of MHC IIb was decreased to 8 +/- 2 (P < 0.001 for both cases). Similarly, this DIA had higher molar ratios (%) of the slow myosin light chain isoforms (i.e. 1sa, 1sb, and 2s), and lower molar ratios of the fast isoforms (i.e. 1f, 2f, and 3f) than control DIA. Heart failure DIA also contained lower proportions of both alpha-tropomyosin and fast isoforms of troponin-T, I and C than control DIA. These results indicate that heart failure elicits fast-to-slow transformations of both myosin and regulatory proteins of human costal DIA. These changes can be viewed as an increase in slow-twitch characteristics of the DIA and differ from the adaptations elicited by heart failure in limb muscles.
我们运用一维和二维电泳技术，描述了慢性充血性心力衰竭引发的人体肋膈（DIA）肌原纤维蛋白比例的变化。在对照组受试者的DIA中发现了三种肌球蛋白重链（MHC）亚型：慢肌球蛋白重链I（43±标准误2%）、快肌球蛋白重链IIa（41±2%）和快肌球蛋白重链IIb（17±1%）。在心力衰竭患者的DIA中，MHC I的百分比增加到57±2%，而MHC IIb的百分比降至8±2（两种情况P均<0.001）。同样，与对照DIA相比，该DIA中慢肌球蛋白轻链亚型（即1sa、1sb和2s）的摩尔比（%）更高，而快肌球蛋白轻链亚型（即1f、2f和3f）的摩尔比更低。心力衰竭患者的DIA中α-原肌球蛋白以及肌钙蛋白-T、I和C的快肌球蛋白轻链亚型比例也低于对照DIA。这些结果表明，心力衰竭会引发人体肋膈DIA中肌球蛋白和调节蛋白从快到慢的转变。这些变化可被视为DIA慢肌纤维特征的增加，且与心力衰竭在肢体肌肉中引发的适应性变化不同。
