Arnold M, Kummermehr J, Trott K R
Institut für Strahlenbiologie, GSF-Forschungszentrum für Umwelt und Gesundheit, Oberschleissheim, Germany.
Radiat Res. 1995 Jul;143(1):77-84.
The femora of adult Wistar rats were locally irradiated with single doses of X rays and 1 day later were wounded by a standardized drilling defect that extended through the diaphyseal cortex into the marrow cavity. Healing of the lesion was followed over 30 weeks to assess the time course of osseous closure. In unirradiated bones healing was complete by week 7. Irradiation with doses up to 15 Gy imparted a dose-dependent delay in the formation of primary callus and its subsequent replacement by more mature bone, while after higher doses healing remained permanently compromised or even suppressed. Using histomorphometry, osseous closure was also measured quantitatively for healing periods of 7, 10, 16 and 30 weeks and the data were expressed as the percentage of responders with < or = 40% fractional closure. The resulting dose-response curves were steep, displaying a large threshold dose and ED50 values between 16.8 to 17.5 Gy (7 to 16 weeks) and 19.4 Gy (30 weeks), respectively.
对成年Wistar大鼠的股骨进行单次X射线局部照射，1天后通过标准化钻孔缺损造成损伤，该缺损延伸穿过骨干皮质进入骨髓腔。对损伤的愈合情况进行了30周的跟踪，以评估骨闭合的时间进程。在未受照射的骨骼中，到第7周时愈合完成。照射剂量高达15 Gy时，会导致初级骨痂形成出现剂量依赖性延迟，以及随后被更成熟的骨组织替代的过程延迟，而更高剂量照射后，愈合会永久性受损甚至被抑制。使用组织形态计量学方法，还对7周、10周、16周和30周愈合期的骨闭合情况进行了定量测量，数据表示为骨闭合分数≤40%的反应者百分比。所得的剂量反应曲线很陡，显示出较大的阈剂量，ED50值分别在16.8至17.5 Gy（7至16周）和19.4 Gy（30周）之间。
