利用兰州重离子研究装置(HIRFL)提供的高能12C6+离子束(能量为300 MeV/u,剂量率为0.5Gy/min)辐照大鼠离体胸主动脉环,考察了12C6+离子束辐照对主动脉环内皮依赖性舒张功能的影响,并采用NBT还原法测定血管环生成超氧阴离子(O 2)水平,加...利用兰州重离子研究装置(HIRFL)提供的高能12C6+离子束(能量为300 MeV/u,剂量率为0.5Gy/min)辐照大鼠离体胸主动脉环,考察了12C6+离子束辐照对主动脉环内皮依赖性舒张功能的影响,并采用NBT还原法测定血管环生成超氧阴离子(O 2)水平,加入外源性超氧化物歧化酶(SOD)干预探讨了O 2在内皮功能损伤中的作用。研究结果表明,2.0,4.0和6.0 Gy的12C6+离子束辐照大鼠胸主动脉环后,可致血管内皮依赖性舒张功能的剂量依赖性明显受损(P<0.01 vs control group),并可致血管环NBT还原能力剂量依赖性增加(4.0 Gy时,P<0.05;6.0 Gy时,P<0.01 vs control group)。辐照前加入外源性SOD对6.0 Gy12C6+离子束辐照所致血管环NBT还原能力升高有明显抑制作用(P<0.01),对血管环内皮依赖性舒张功能也有明显的保护作用(P<0.01),但辐照后10 min加入外源性SOD,其保护作用明显不及前者。结论显示,12C6+离子束辐照大鼠胸主动脉环可致血管内皮功能受损,O 2清除剂SOD对内皮功能受损有保护作用,说明O 2介导了辐照所致内皮功能损伤。展开更多
The effects of 12C＋6 ion irradiation on colony morphology and mycelia morphology, as well as on mutation rate have been studied in the B1a high-product strains （ZJAV-Y1-203） mutated by heavy ion irradiation and com...The effects of 12C＋6 ion irradiation on colony morphology and mycelia morphology, as well as on mutation rate have been studied in the B1a high-product strains （ZJAV-Y1-203） mutated by heavy ion irradiation and compared with that in the original strain （ZJAV-A-1）. After irradiating the rate of a straw hat colony type having a high ability of producing B1a in ZJAV-Y1-203 strains was higher than that found in ZJAV-A-1 strains. When strains were cultured in a liquid medium for 24 hours, the mycelium becoming thinner could be observed in all of the irradiated ZJAV- Y1-203 groups, but only in the ZJAV-A-1 groups irradiated at the dose of 50 Gy or more. The early growth of mycelium was inhibited in the ZJAV- Y1-203 group irradiated with a high dose. The highest positive mutation rate （23.5%） of ZJAV - Y1 - 203 was reached at the lower dose of 30 Gy while the highest positive mutation rate of 34.2% in ZJAV-A-1 appeared at 50 Gy. These results indicate that the effects of heavy ion irradiation still exist even in the mutated Streptomyces avermitilis, and only the dose is lower and the effects not so strong compared with the one that is first irradiated with optimized heavy ion doses. This is evidence of the one directional mutation being controlled by many more factors in a organism.展开更多
文摘利用兰州重离子研究装置(HIRFL)提供的高能12C6+离子束(能量为300 MeV/u,剂量率为0.5Gy/min)辐照大鼠离体胸主动脉环,考察了12C6+离子束辐照对主动脉环内皮依赖性舒张功能的影响,并采用NBT还原法测定血管环生成超氧阴离子(O 2)水平,加入外源性超氧化物歧化酶(SOD)干预探讨了O 2在内皮功能损伤中的作用。研究结果表明,2.0,4.0和6.0 Gy的12C6+离子束辐照大鼠胸主动脉环后,可致血管内皮依赖性舒张功能的剂量依赖性明显受损(P<0.01 vs control group),并可致血管环NBT还原能力剂量依赖性增加(4.0 Gy时,P<0.05;6.0 Gy时,P<0.01 vs control group)。辐照前加入外源性SOD对6.0 Gy12C6+离子束辐照所致血管环NBT还原能力升高有明显抑制作用(P<0.01),对血管环内皮依赖性舒张功能也有明显的保护作用(P<0.01),但辐照后10 min加入外源性SOD,其保护作用明显不及前者。结论显示,12C6+离子束辐照大鼠胸主动脉环可致血管内皮功能受损,O 2清除剂SOD对内皮功能受损有保护作用,说明O 2介导了辐照所致内皮功能损伤。
基金Supported by Western Light Talents Training Program of Chinese Academy of Sciences(O906050XB0)Grant Science and Technology Projects in Lanzhou(2009-2-13)
文摘The effects of 12C＋6 ion irradiation on colony morphology and mycelia morphology, as well as on mutation rate have been studied in the B1a high-product strains （ZJAV-Y1-203） mutated by heavy ion irradiation and compared with that in the original strain （ZJAV-A-1）. After irradiating the rate of a straw hat colony type having a high ability of producing B1a in ZJAV-Y1-203 strains was higher than that found in ZJAV-A-1 strains. When strains were cultured in a liquid medium for 24 hours, the mycelium becoming thinner could be observed in all of the irradiated ZJAV- Y1-203 groups, but only in the ZJAV-A-1 groups irradiated at the dose of 50 Gy or more. The early growth of mycelium was inhibited in the ZJAV- Y1-203 group irradiated with a high dose. The highest positive mutation rate （23.5%） of ZJAV - Y1 - 203 was reached at the lower dose of 30 Gy while the highest positive mutation rate of 34.2% in ZJAV-A-1 appeared at 50 Gy. These results indicate that the effects of heavy ion irradiation still exist even in the mutated Streptomyces avermitilis, and only the dose is lower and the effects not so strong compared with the one that is first irradiated with optimized heavy ion doses. This is evidence of the one directional mutation being controlled by many more factors in a organism.
