Marijianowski M M, Teeling P, Mann J, Becker A E
Department of Cardiovascular Pathology, Academic Medical Center, Amsterdam, The Netherlands.
J Am Coll Cardiol. 1995 May;25(6):1263-72. doi: 10.1016/0735-1097(94)00557-7.
The aim of this study was to quantify total collagen and the type I/type III collagen ratio and their localization in hearts with dilated cardiomyopathy.
Patients with dilated cardiomyopathy have an increase in intramyocardial fibrillar collagen. Types I and III are the main constituents and have different physical properties that may affect cardiac compliance.
Nineteen hearts with dilated cardiomyopathy were studied (17 cardiac explants, 2 hearts obtained at autopsy) and compared with reference hearts. Total collagen was determined by hydroxyproline analysis. Collagen types I and III were analyzed using the cyanogen bromide method and immunohistochemical analysis followed by microdensitophotometric quantification. Localization of collagen types I and III was established at the light and electron microscopic levels. Immunoelectron microscopy provided information regarding their localization.
Total collagen and the collagen type I/type III ratio were increased in hearts with dilated cardiomyopathy (p < 0.05). Electron microscopy showed a diffuse increase in collagen fibrils in the endomysium; the perimysium showed an inhomogeneous increase. Collagen fibrils were thicker, and fibrous long-spacing collagen occurred in the endomysium. Immunoelectron microscopic findings confirmed an increase in type I collagen.
Hearts with dilated cardiomyopathy have a statistically significant increase in the collagen type I/type III ratio. The changes occur in the endomysium and perimysium, although with differences in distribution. These changes in intramyocardial collagen may be clinically relevant because they may affect cardiac rigidity and, therefore, eventually may render the heart less compliant. Further studies are needed to evaluate at what point in the course of the disease these changes appear.
本研究旨在量化扩张型心肌病心脏中的总胶原蛋白、I型/III型胶原蛋白比例及其定位。
扩张型心肌病患者心肌内纤维状胶原蛋白增加。I型和III型是主要成分，具有不同的物理特性，可能影响心脏顺应性。
对19例扩张型心肌病心脏进行研究（17例心脏移植标本，2例尸检心脏），并与对照心脏进行比较。通过羟脯氨酸分析测定总胶原蛋白。使用溴化氰法和免疫组织化学分析，随后进行显微密度光度法定量分析I型和III型胶原蛋白。在光镜和电镜水平确定I型和III型胶原蛋白的定位。免疫电子显微镜提供了有关它们定位的信息。
扩张型心肌病心脏中的总胶原蛋白和I型/III型胶原蛋白比例增加（p < 0.05）。电子显微镜显示肌内膜中胶原纤维弥漫性增加；肌束膜显示不均匀增加。肌内膜中的胶原纤维更粗，且出现了纤维状长间距胶原蛋白。免疫电子显微镜结果证实I型胶原蛋白增加。
扩张型心肌病心脏的I型/III型胶原蛋白比例在统计学上有显著增加。这些变化发生在肌内膜和肌束膜，尽管分布存在差异。心肌内胶原蛋白的这些变化可能具有临床相关性，因为它们可能影响心脏硬度，最终可能使心脏顺应性降低。需要进一步研究以评估这些变化在疾病过程中的出现时间点。
