【摘要】 目的　观察高压氧后低氧放疗对小鼠肿瘤组织和正常组织的影响。方法　实验用C57BL 6小鼠 ,共设 5组 :空白对照组 ,单纯放疗组 (单放组 ) ,单纯低氧放疗组 (LO组 ) ,单纯高压氧放疗组 (HBO组 ) ,高压氧后低氧放疗组 (HBO +LO组 )。单次大剂量 6MeV电子束一次给予 2 0Gy,高压氧条件为 2 5个绝对大气压 ,10 0min。低氧条件为 10 5 %的低氧混合气 ,各组小鼠均经鼠尾静脉注射 5 5 5mBq 0 2ml99mTc HL91后 12 0min进行ECTγ显像。结果　 (1)HBO组和HBO +LO组的小鼠肿瘤平均生长延迟天数明显长于其他各组 ,对肿瘤抑制作用相近。 (2 )LO组和HBO +LO组的小鼠平均存活天数明显长于其他各组 ,保护正常组织 ,延长寿命效应相近。 (3)HBO组和HBO +LO组乏氧组织显像剂放射性计数比值明显低于其他各组 ,两组间差异无显著性。结论　高压氧后低氧放疗对小鼠肿瘤组织有放射增敏作用而且对正常组织有放射防护作用。更多还原

【Abstract】 Objective To observe the effect of hypoxic irradiation following hyperbaric oxygen therapy on murine tumor tissue and normal tissue. Methods C 57 BL/6 mice implanted with Lewis lung cancer were divided into five groups :the irradiation group,the hypoxic irradiation group (LO), the hyperbaric oxygen irradiation group(HBO), the hyperbaric oxygen plus hypoxic irradiation group(HBO+LO) and the control group.The experiment was started when the transplanted tumor reached 1.0～2.0 cm.A dose of 20 Gy 6 MeV electron beam of DT was used for irradiation. Two and half atmosphere pressure of hyperbaric oxygen was given for 100 minutes during therapy and a mixture of 10.5% oxygen and 89.5%N 2 was provided for hypoxic irradiation.ECT γ images were taken 120 mins after 99 m Tc-HL91 injection. Results (1)The mean murine tumor growth rate in both HBO group and HBO+LO group delayed significantly than that in other groups.(2)The survival times of both LO group and HBO+LO group were significantly longer than those of other groups.These two groups showed almost the same effect in protecting normal tissues and prolonging lives.(3)The imaging agent radioactivity ratio of tumor to contralateral(T/A)tissues in both HBO and HBO+LO groups decreased significantly than that in other groups.And no difference in the therapeutic effect was found in these two groups. Conclusion The hypoxic irradiation following hyperbaric oxygen therapy might achieve a radiation-enhancing effect on tumor cells and a protective effect on normal tissues.更多还原