Lombard-Vignon N, Lafuma C, Godeau G, Masse R
Centre d'Etudes Nucléaires de Fontenay-aux-Roses, France.
Int J Radiat Biol. 1990 Aug;58(2):325-40. doi: 10.1080/09553009014551661.
The initial response to local gamma-irradiation of skin was investigated in fibroblasts from cutaneous explants after doses of 4, 8, 12, 16 or 20 Gy. On the day of irradiation, fibroblast outgrowth was inhibited in a dose-dependent manner, but by day 7 post-irradiation, cell restoration occurred especially in explants exposed to 4 or 8 Gy. The dose-dependent inhibition of fibroblast outgrowth correlated with the decrease in cellular metallo-endopeptidase (MEP) activity against succinyl trialanine paranitroanilide. However, the secretion of this MEP activity was 10-fold higher in the culture medium after the lowest irradiation dose (4 Gy). Its inhibition profile was not modified after local irradiation, whatever the dose. In vivo, the cell density of mastocytes, pericytes and endothelial cells decreased after irradiation. Moreover, damaged collagen was observed in the superficial dermis after local irradiation. These results strongly suggest that this MEP may be involved in the alterations occurring in dermal connective tissue components after skin irradiation. The rapid decrease with the dose in fibroblast outgrowth and MEP activity also suggests that these two parameters may provide useful tools for dosimetric assay of the heterogeneity and extent of irradiated areas.
研究了皮肤外植体来源的成纤维细胞在接受4、8、12、16或20 Gy剂量局部γ射线照射后的初始反应。在照射当天，成纤维细胞的生长以剂量依赖性方式受到抑制，但在照射后第7天，细胞出现恢复，尤其是在接受4或8 Gy照射的外植体中。成纤维细胞生长的剂量依赖性抑制与细胞金属内肽酶（MEP）对琥珀酰丙氨酰对硝基苯胺的活性降低相关。然而，在最低照射剂量（4 Gy）后，培养基中这种MEP活性的分泌高出10倍。无论剂量如何，局部照射后其抑制模式均未改变。在体内，照射后肥大细胞、周细胞和内皮细胞的细胞密度降低。此外，局部照射后在浅表真皮中观察到胶原受损。这些结果强烈表明，这种MEP可能参与皮肤照射后真皮结缔组织成分发生的改变。成纤维细胞生长和MEP活性随剂量迅速下降也表明，这两个参数可能为照射区域的异质性和范围的剂量测定提供有用工具。
