Wegrowski J, Lafuma C, Lefaix J L, Daburon F, Robert L
Laboratoire de Biochimie du tissu Conjonctif, UA CNRS 1174, Faculté de Médecine, Université Paris Val de Marne, Créteil, France.
Exp Mol Pathol. 1988 Jun;48(3):273-85. doi: 10.1016/0014-4800(88)90064-0.
Six months after acute local gamma irradiation of the pig skin and adjacent muscle, the muscular tissue is replaced by a large mutilating and proliferative fibrosis deliminated by a perifibrotic inflammatory zone. The content and biosynthesis of collagen and noncollagenous proteins were studied in both fibrotic and perifibrotic zones after incubation of the biopsies with [14C]proline or [35S]methionine for 24 hr. Cells of perifibrotic and fibrotic regions synthesize about 10 times more proteins than those in the nonirradiated muscle. When compared to normal muscle tissue, our results indicate an important increase in collagen content and biosynthesis in fibrotic tissue. The increase in collagen biosynthesis in the irradiated tissue is more pronounced for type III collagen than for type I collagen. Biosynthesis of type III and type I collagens increases 20- and 10-fold, respectively, compared to the normal muscle. Type I to III collagen ratio in irradiated tissue decreases from 2.3 in normal tissue to 1.1 in fibrotic tissue. Histological examination of the biopsies as well as the protein pattern by polyacrylamide gel electrophoresis show striking differences in the perifibrotic and fibrotic areas as compared to the normal muscular tissue with a progressive disappearance of the myotubes replaced by a dense sclerotic tissue. The results indicate that the perifibrotic inflammatory area is engaged in a remodeling process and that the fibrotic tissue remains active in the neosynthesis of the extracellular matrix macromolecules with a high proportion of type III collagen. This high biosynthetic activity of the irradiated tissue may explain the pseudosarcomatous character of the radiation-induced lesions.
猪皮肤及相邻肌肉局部急性γ射线照射六个月后，肌肉组织被大片致残性增生性纤维化所取代，周围有纤维化炎症区界定。在活检组织与[¹⁴C]脯氨酸或[³⁵S]甲硫氨酸孵育24小时后，对纤维化区和纤维化周围区的胶原蛋白和非胶原蛋白的含量及生物合成进行了研究。纤维化周围区和纤维化区的细胞合成的蛋白质比未照射肌肉中的细胞多约10倍。与正常肌肉组织相比，我们的结果表明纤维化组织中的胶原蛋白含量和生物合成显著增加。照射组织中III型胶原蛋白的生物合成增加比I型胶原蛋白更明显。与正常肌肉相比，III型和I型胶原蛋白的生物合成分别增加了20倍和10倍。照射组织中I型与III型胶原蛋白的比例从正常组织中的2.3降至纤维化组织中的1.1。活检组织的组织学检查以及聚丙烯酰胺凝胶电泳的蛋白质图谱显示，与正常肌肉组织相比，纤维化周围区和纤维化区存在显著差异，肌管逐渐消失，被致密的硬化组织取代。结果表明，纤维化周围炎症区参与了重塑过程，纤维化组织在细胞外基质大分子的新合成中保持活跃，其中III型胶原蛋白比例较高。照射组织的这种高生物合成活性可能解释了辐射诱导损伤的假肉瘤特征。
