Morishita N, Kusachi S, Yamasaki S, Kondo J, Tsuji T
First Department of Internal Medicine, Okayama University Medical School, Japan.
Jpn Circ J. 1996 Feb;60(2):108-14. doi: 10.1253/jcj.60.108.
The healing process, which affects ventricular remodeling, is an important factor in the prognosis of myocardial infarction. We hypothesized that laminin and type IV collagen contribute to extracellular matrix assembly in healing after myocardial infarction. We examined sequential changes in these two components after experimental myocardial infarction in rats.
Hearts were excised from 1 day to 10 weeks after permanent left coronary ligation in rats. Immunohistochemical staining with a polyclonal antibody to laminin and type IV collagen was performed by the avidin-biotin-peroxidase method.
Laminin: On day 3, laminin initially appeared in a wavy fashion in the granulation tissue of the infarct peripheral zone and was not restricted to the cell membrane; the staining distribution in the peripheral zone then gradually increased, reaching a maximum on days 7-11. The distribution progressed from the peripheral zone to the outer lesion of the central zone of the infarct for 1-2 days, and reached the center point after 2 weeks. The extent of the staining distribution gradually decreased after reaching this maximum, but the staining did not completely disappear. Type IV Collagen: Changes in type IV collagen were essentially the same as those in laminin. A wavy staining pattern of type IV collagen appeared in the infarct peripheral zone from day 3, reached its maximum extent on days 7-11, and decreased gradually thereafter. The distribution progressed from the peripheral zone to the outer lesion of the central zone for 1-2 days, reaching the center point after 2 weeks.
Laminin and type IV collagen contribute to extracellular matrix formation in the infarct zone relatively early after myocardial infarction.
影响心室重构的愈合过程是心肌梗死预后的一个重要因素。我们推测层粘连蛋白和IV型胶原在心肌梗死后的愈合过程中有助于细胞外基质的组装。我们研究了大鼠实验性心肌梗死后这两种成分的动态变化。
在大鼠永久性结扎左冠状动脉后1天至10周切除心脏。采用抗生物素蛋白-生物素-过氧化物酶法，用抗层粘连蛋白和IV型胶原的多克隆抗体进行免疫组织化学染色。
层粘连蛋白：在第3天，层粘连蛋白最初以波浪状出现在梗死周边区的肉芽组织中，并不局限于细胞膜；随后周边区的染色分布逐渐增加，在第7 - 11天达到最大值。分布在1 - 2天内从周边区向梗死中央区的外侧病变进展，2周后到达中心点。染色分布范围在达到最大值后逐渐减小，但染色并未完全消失。IV型胶原：IV型胶原的变化与层粘连蛋白基本相同。从第3天起，IV型胶原在梗死周边区出现波浪状染色模式，在第7 - 11天达到最大范围，此后逐渐减小。分布在1 - 2天内从周边区向中央区的外侧病变进展，2周后到达中心点。
层粘连蛋白和IV型胶原在心肌梗死后相对早期有助于梗死区细胞外基质的形成。
