Lefaix J L, Daburon F, Martin M, Rémy J
CEA, IPSN-DPS-SPE, Laboratoire de Radiobiologie Appliquée, Gif-sur-Yvette, France.
Pathol Biol (Paris). 1990 Jun;38(6):617-25.
This study was performed on an experimental porcine model of acute local gamma irradiation to simulate accidents which occurred among humans. It enabled us to determine the development and the physiopathological characteristics of the fibrous tissue which developed in skeletal muscle. In the first month after irradiation, the strong inflammatory reaction which initiated the radiation induced fibrosis was characterized by edema as visualized on MRI imaging and X rays computed tomography and by acute phase reactant proteins changes, associated with elevations of local and general temperatures in irradiated animals. At the margin of the irradiated tissue myofibroblasts isolated among collagen bundles or grouped in nodullary reinforcements, are seen associated with intense capillary neogenesis. Several months after irradiation normal skeletal muscle was replaced by atrophic fibrosis delimited by an inflammatory perifibrotic tissue. The muscular fibrosis was characterized by a high density of myofibroblasts and by an inflammatory distribution pattern of collagen types I, III, IV, laminin, fibronectin and fibrinogen as visualized by immunohistochemical methods. Biochemical results showed an increase in collagen content and synthesis in fibrotic tissue whereas the cells in the perifibrotic zone synthesized more non collagenous proteins as compared with the normal muscle. The contributions of granulation tissue, cellular mediators and inhibition of muscular regeneration in the persistence of the invasive character of the muscular radiation induced fibrosis are discussed.
本研究在急性局部伽马辐射的实验猪模型上进行，以模拟人类发生的事故。这使我们能够确定骨骼肌中形成的纤维组织的发展情况及其生理病理特征。在辐射后的第一个月，引发辐射诱导纤维化的强烈炎症反应的特征是，通过磁共振成像（MRI）和X射线计算机断层扫描可见水肿，以及急性期反应蛋白的变化，同时受辐射动物的局部和全身温度升高。在受辐射组织的边缘，可以看到在胶原束之间分离或聚集在结节状增强物中的肌成纤维细胞，伴有强烈的毛细血管新生。辐射数月后，正常骨骼肌被萎缩性纤维化取代，周围是炎症性纤维组织。通过免疫组织化学方法可见，肌肉纤维化的特征是肌成纤维细胞密度高，以及I、III、IV型胶原蛋白、层粘连蛋白、纤连蛋白和纤维蛋白原的炎症分布模式。生化结果显示，纤维化组织中的胶原蛋白含量和合成增加，而与正常肌肉相比，纤维组织周围区域的细胞合成了更多的非胶原蛋白。本文讨论了肉芽组织、细胞介质以及肌肉再生抑制在肌肉辐射诱导纤维化侵袭性持续存在中的作用。
