Changes in extracellular collagen matrix alter myocardial systolic performance
Changes in extracellular collagen matrix alter myocardial systolic performance
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DOI：
10.1152/ajpheart.00233.2002
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发表时间：
2003-01-01
影响因子：
4.8
通讯作者：
Zile, MR
中科院分区：
文献类型：
--
作者：
Baicu, CF;Stroud, JD;Zile, MR
本研究的目的是检验以下假设：急性破坏纤维胶原蛋白会降低心肌收缩性能，而不会改变心肌细胞的收缩力。分离的乳头肌用纤溶酶（0.64U/ml，240分钟）处理或未处理，并用作相同的动物对照。纤溶酶治疗引起基质金属蛋白酶激活和胶原降解明胶酶谱法，羟脯氨酸测定，扫描电子显微镜。纤溶酶引起心肌收缩性能显著下降。等张缩短程度和等长收缩张力从未处理肌肉的0.17 +/- 0.01肌肉长度（ML）和45 +/- 4 mN/mm（2）降低到处理肌肉的0.09 +/- 0.01 ML和36 +/- 3 mN/mm（2）（P < 0.05）。然而，纤溶酶处理（0.64 U/ml，240分钟）并没有改变缩短的程度或速度在分离的心肌细胞。纤维胶原网络的急性破坏导致心肌收缩性能下降，而不改变心肌细胞收缩力。这些数据支持这样的假设，即纤维状胶原促进心肌细胞收缩转化为心肌力的发展，并有助于维持正常的心肌收缩性能。
The purpose of this study was to test the hypothesis that acute disruption of fibrillar collagen will decrease myocardial systolic performance without changing cardiomyocyte contractility. Isolated papillary muscles were treated either with plasmin (0.64 U/ml, 240 min) or untreated and served as same animal control. Plasmin treatment caused matrix metalloproteinase activation and collagen degradation as measured by gelatin zymography, hydroxyproline assays, and scanning electron microscopy. Plasmin caused a significant decrease in myocardial systolic performance. Isotonic shortening extent and isometric developed tension decreased from 0.17 +/- 0.01 muscle length (ML) and 45 +/- 4 mN/mm(2) in untreated muscles to 0.09 +/- 0.01 ML and 36 +/- 3 mN/mm(2) in treated muscles (P < 0.05). However, plasmin treatment (0.64 U/ml, 240 min) did not alter shortening extent or velocity in isolated cardiomyocytes. Acute disruption of the fibrillar collagen network caused a decrease in myocardial systolic performance without changing cardiomyocyte contractility. These data support the hypothesis that fibrillar collagen facilitates transduction of cardiomyocyte contraction into myocardial force development and helps to maintain normal myocardial systolic performance.