不同吸氧方式对小鼠小肠上皮放射效应的影响

①目的　观察放射治疗时 ,不同吸氧方式对小鼠小肠上皮生物效应的影响。②方法　昆明小鼠随机分为空气组、高氧组、低氧组、高 低氧组。用 6MV X线不同剂量全腹腔单次照射。配合剂量效应曲线 ,求出不同吸氧方式的放射防护系数 (RPF)。并用图像分析仪测定 6Gy各组隐窝区表皮生长因子受体 (EGFR)的相对含量。③结果　高氧组碳合氧的吸入显示了放射增敏作用 ,其RPF为 0 .79。低氧组低氧放疗具有放射防护作用 ,其RPF为 1.2 5。高 低氧组高 低氧放疗也表现出一定的放射防护作用 ,其RPF为 1.0 6。高 低氧组与空气组EGFR的表达无统计学意义 (F =6 .10 ,q =2 .90 ,P >0 .0 5 ) ,而高氧组和低氧组与空气组相比 ,EGFR的表达分别为减少和增加 ,差异有统计学意义 (q =3.4 0、4 .96 ,P <0 .0 5 )。 ④结论　EGFR免疫组化定量可能是早期标志放射损伤的指标之一。高 低氧放疗中低氧的加入不仅消除了碳合氧吸入加重的小肠上皮的放射损伤 ,在一定程度上还具有放射防护作用

EFFECTS OF VARIOUS WAYS OF OXYGEN INHALATION ON RADIATION RESPONSE OF MURINE INTESTINAL EPITHELIUM

Objective To investigate the effects of various ways of oxygen inhalation on radiation response of murine intestinal epithelium. Methods Kunming mice were divided into four groups in random: Air, HO, LO and HO+LO Groups. The abdomens of mice were radiated with 6 MV X-rays in single dose. The relationship between total cell survival per circumference and radiation dose was established, and dose-survival curves fitted. Radioprotective factors(RPF) were calculated. The expression of epidermal growth factor receptor(EGFR) in crypts that received 6 Gy was quantitated by a computer image analysis system. Results HO Group: its RPF was 0.79 ; LO Group: RPF was 1.25; HO+LO Group: RPF was 1.06. The difference of expression of EGFR between HO+LO Group and Air Group was not statistically significant (F=6.10, q=2.90, P>0.05), while EGFR in HO Group was reduced and that in LO Group increased significantly as compared with Air Group (q=3.40,4.96,P<0.05), respectively. Conclusion The expression of EGFR may be an indicator of radiation damage in earlier stage. The inhalation of low concentration of oxygen not only indicates some degree of radioprotective effects, but also can eradicate the enhanced damage caused by carbogen.