Left ventricular perimysial collagen fibers uncoil rather than stretch during diastolic filling
Left ventricular perimysial collagen fibers uncoil rather than stretch during diastolic filling
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DOI：
10.1007/bf00799683
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发表时间：
1996-03-01
影响因子：
9.5
通讯作者：
Covell, JW
中科院分区：
文献类型：
--
作者：
MacKenna, DA;Omens, JH;Covell, JW
心肌中的胶原纤维最初呈波浪形，表明它们可能没有被直接拉伸以进行部分舒张充盈。为了测试纤维是否逐渐变直，以及在多大左室压下它们变直，对24只离体停搏大鼠心脏进行了实验；检查左室生理性舒张压和胶原结构的变化。随着左室压的升高，平均（+/- se）肌节长度增加（从0 mmHg到26.3 +/- 4.1 mmHg, 1.80 +/- 0.02到1.88 +/- 0.02），而膜周纤维的弯曲度（纤维长度/中线长度）减小（从0 mmHg到26.3 +/- 4.1 mmHg, 1.088 +/- 0.014到1.031 +/- 0.006）。跨壁胶原结构的变化与肌节长度的变化趋势相似（心外膜区域的肌节较长，胶原纤维比心内膜区域更直）。这些结果表明，黏膜周围胶原纤维与肌细胞之间存在紧密耦合，与非线性压力-体积和压力-肌节长度关系一致。
The collagen fibers in the myocardium are initially wavy, suggesting that they may not be directly stretched for a portion of diastolic filling. To test whether the fibers gradually straighten and at what left ventricular (LV) pressure they become straight, 24 isolated, arrested rat hearts were fir;ed at physiologic diastolic LV pressures and changes in collagen structure were examined. As LV pressure increased, mean (+/-SE) sarcomere length increased (1.80 +/- 0.02 to 1.88 +/- 0.02 from 0 mmHg to 26.3 +/- 4.1 mmHg) while the tortuosity of the perimysial fibers (fiber length/ midline length) decreased (1.088 +/- 0.014 to 1.031 +/- 0.006 from 0 mmHg to 26.3 +/- 4.1 mmHg). Transmural variations in collagen structure paralleled the trends in sarcomere length (epicardial regions had longer sarcomeres and straighter collagen fibers than endocardial regions). These results indicate that there is a tight coupling between perimysial collagen fibers and myocytes, consistent with the nonlinear pressure-volume and pressure-sarcomere length relationships.