葛根黄酮的辐射防护及其机制的研究

目的研究葛根黄酮对受照射小鼠的辐射防护作用及其作用机制。方法采用^60Coγ射线照射小鼠模型，观察8Gy照射小鼠30d存活和死亡动物存活时间。在低剂量照射模型观察用药后外周血指标和脏器系数变化，用原位末端标记法观察受照射小鼠脾细胞凋亡，流式细胞仪检测脾细胞凋亡率，同时检测血清中抗氧化酶和脂质过氧化物水平。结果照前给予葛根黄酮能明显提高受照射小鼠的存活率。葛根黄酮能明显促进受低剂量（5Gy）照射后小鼠的外周血白细胞恢复，提高受照小鼠的胸腺和脾脏指数，抑制受照射小鼠脾细胞凋亡，降低脾细胞内的caspase-3活性，降低脂质过氧化物水平。结论葛根黄酮具有明显的辐射防护作用，效果明显优于愈风宁心片。葛根黄酮抗辐射作用机制可能与抑制辐射敏感细胞的细胞凋亡和抗氧化作用有关。     

电离辐射后小鼠骨髓组成中结合珠蛋白的表达规律研究

目的研究照射前后结合珠蛋白在小鼠骨髓中的表达和分布，及其与骨髓细胞周期进程改变及凋亡的可能关联。方法用RT-PCR，Western blotting及流式细胞术的方法检测骨髓细胞Hp mRNA及细胞内外Hp蛋白的存在，及其辐射后的变化。用流式细胞术的方法分析了骨髓细胞中Hp阴性及阳性细胞群周期分布及凋亡率的差异。结果在骨髓细胞中检测到Hp mRNA的存在，而且8Gy照射后24h较正常小鼠有明显升高。骨髓细胞内及外液中检测到Hp蛋白的存在，同样8Gy照射后24h较正常小鼠亦呈明显升高。流式细胞术检测发现小鼠骨髓细胞中部分细胞含有Hp蛋白，照射后Hp阳性细胞的比例逐渐增加，并有着较好的时效关系和剂量依赖关系。骨髓Hp阳性细胞与阴性细胞的细胞周期分布存在显著的差异。在照射后6h骨髓细胞凋亡率随照射剂量增加而明显增加，而Hp^ 细胞凋亡率增加不明显。结论小鼠骨髓组织中可以检测到结合珠蛋白的存在，并且在辐射后有明显的增加，骨髓细胞中Hp阴、阳性细胞的周期分布和凋亡存在明显的差异。推测Hp可能参与辐射诱导骨髓损伤的修复过程。     

小鼠脾细胞培养上清中的粒系造血活性及其照射后的改变

观察了小鼠脾脏，胸腺和骨髓细胞培养上清中的粒系造血刺激活性和抑制活性及其在照射后的改变。结果表明，正常小鼠脾细胞培养上清中有一定的造血刺激活性，抑制活性不明显，经３、５、７、８、９Ｇｙ不同剂量照射后早期造血刺激活性随之降低，大剂量照射可降至零。１２￣１４ｄ刺激活性有所恢复。大剂量照后早期小鼠脾细胞培养上清中有一定的抑制活性，照后小鼠的胸腺、骨髓细胞培养上清中未见明显的粒系造血刺激活性，大剂量照射仅     

小鼠受γ射线全身照射后FL表达变化的研究

目的 FL(fit3 ligand)是一种作用于早期造血细胞的生长因子，为进一步研究FL水平与辐射所致造血损伤的相关性，观察了小鼠受γ射线全身照射后FL的表达变化。方法以^60Coγ射线全身一次性均匀照射所致骨髓型急性放射病小鼠为模型，应用ELISA、流式细胞术、Western blot法检测照射前后小鼠外周血、骨髓、胸腺与脾脏中FL的表达变化。结果 小鼠受2～10Gyγ射线照射后24h，血清中FL浓度即有增加，并且随时间推移FL水平逐渐升高；吸收剂量在2～6Gy之间时，FL的水平随剂量增加而增加。6Gyγ射线照射后24h，外周血白细胞膜表面FL的表达增加，但24h后细胞膜表面FL的表达没有升高。6Gyγ射线照射后24h，骨髓、胸腺和脾脏有核细胞膜表面FL的表达明显升高，总蛋白中FL的水平亦明显增加。结论 辐射后早期小鼠FL可溶性与膜结合型蛋白的水平都有升高，而且辐射后血清中FL的水平与受照剂量及照射后时间存在相关性。     

钬激光照射后人T-24膀胱癌细胞株中半胱天冬酶-3蛋白的表达及其意义

目的观察钬激光照射后人T-24膀胱癌细胞株中半胱天冬酶（Caspase）-3蛋白的表达，探讨其在T私细胞发生凋亡中的作用。方法取对数生长期人T-24膀胱癌细胞株，分对照组与实验组，试验组以800mJ钬激光直接照射而对照组仅以指示光照射不激发激光能量，照射后48h分别在光镜下观察细胞形态学的改变，免疫细胞化学染色检测半胱天冬酶．3蛋白在T-24细胞中的表达。结果800mJ钬激光照射后实验组细胞形态呈现出凋亡改变，半胱天冬酶-3蛋白呈现阳性表达。结论钬激光照射人T-24膀胱癌细胞株，可诱发肿瘤细胞凋亡，半胱天冬酶-3蛋白在诱导T-24细胞凋亡中可能发挥重要作用。     

电离辐射对小鼠组织金属硫蛋白-1mRNA表达的影响

目的 探讨X射线全身照射对小鼠肝、脑、胸腺及脾脏金属硫蛋白(MT)-1 mRNA表达的影响及其剂量效应关系。方法 采用Northem杂交方法检测了X射线全身照射后小鼠肝、脑、胸腺及脾脏MT-1 mRNA水平变化。结果 4GyX射线照射后肝脏及胸腺MT-1mRNA水平逐渐升高，照射后4h达峰值，分别为假射组的1．82及1．72倍，24h基本恢复至正常水平；0．5～6Gv照射后4h，肝脏及胸腺MT-1mRNA水平均呈剂量依赖性增加，6Gy照射后MT-1mRNA水平分别为假照组的2．13和1．62倍。但X射线全身照射后小鼠脑及脾脏MT-1mRNA水平未见明显变化。结论 X射线全身照射可提高小鼠肝脏和胸腺MT-1 mRNA水平，但对小鼠脑及脾脏MT-1mRNA表达无影响.     

辐射小鼠骨髓CD34~ 细胞的变化及其意义

目的　研究γ射线照射后C5 7小鼠骨髓中CD34 细胞的数量变化规律及其意义。方法　流式细胞仪测定CD34 细胞在骨髓有核细胞中的比例 ;AnnexinV FITC试剂盒检测骨髓细胞的凋亡 ;细胞固定后PI染色测定细胞周期。结果　①CD34 细胞在骨髓有核细胞中的比例随照射剂量的加大而降低 ,在 5 5Gy照射后 14d内小鼠CD34 细胞的减少表现为持续性 ;②小鼠照射后6h骨髓细胞凋亡率最高 ,以 5 5Gy照射组最为明显 ;③ 5 5Gy照射后小鼠骨髓细胞周期紊乱。 结论　γ射线损伤骨髓中的干祖细胞 ,造成骨髓中干祖细胞的数量减少 ,其途径之一是诱导骨髓细胞凋亡。     

X射线诱导转录因子活化与凋亡的关系

目的 通过观察较高剂量照射的鼠胸腺细胞内几种转录因子活性的变化和胸腺细胞凋亡发展时程，探讨转录因子活性的变化在辐射诱导的免疫细胞凋亡中的作用。方法 通过电泳移动变化分析及流式细胞术的方法分别检测了2Gy X射线全身照射后胸腺细胞内转录因子NF－κB、CREB和OCT－1活性以及胸腺细胞凋亡的动态变化。结果 2Gy X射线全身照射后胸腺细胞内NF－κB两种二聚体p50/p50和p50/p65的DNA结合活性的变化存在着明显的区别，主要以p50/p50活性显著升高为特征，CREB OCT－1的活性也明显增强，活性高峰均出现了照射后4－12h，而它们的活性高峰又恰与2Gy照射诱导的胸腺细胞凋亡的高峰相吻合。结论 较高剂量电离辐射主要诱导NF－κB同源二聚体的DNA结合活性增强；3种转录因子NF－κB p50/50、CREB以及OCT－1可能在2Gy照射诱导的胸腺细胞内具有协同促进细胞凋亡的作用。     

低剂量辐射适应性反应对辐射诱发小鼠胸腺淋巴瘤的影响

目的 探讨低剂量辐射对致癌剂量辐射诱发小鼠胸腺淋巴瘤的影响及其免疫学机理。方法 采用4次1.75GyX射线全身照射C57BL/6J小鼠诱发胸腺淋巴瘤模型, 观察不同剂量照后6个月小鼠胸腺淋巴瘤发生率, 照后1个月脾脏NK细胞毒活性、IL-2和γIFN分泌活性、腹腔巨噬细胞吞噬功能及其TNFα分泌活性以及胸腺细胞分化的变化。结果 每次1.75Gy照射前6h或12h接受25mGy或75mGy全身照射均可降低胸腺淋巴瘤发生率, 且预先接受75mGy全身照射的作用效果更为明显; 每次1.75Gy照射前12h接受75mGy照射小鼠, 上述免疫指标均比单纯1.75Gy照射组增强, 且多数指标接近假照射组; 其胸腺CD4^-CD8^-和CD4^-CD8⁺细胞较单纯1.75Gy照射组减少、CD4⁺CD8⁺细胞增多。结论 低剂量辐射可诱导辐射诱发胸腺淋巴瘤适应性反应, 对致癌剂量辐射诱发小鼠胸腺淋巴瘤有抑制作用, 其抑制作用的免疫学机理可能与低剂量辐射的免疫增强效应及诱导的免疫学适应性反应, 减轻致癌剂量辐射对机体免疫功能的损伤, 使胸腺淋巴瘤前体细胞在形成胸腺淋巴瘤之前被免疫系统清除有关。     

辐射小鼠骨髓CD34+细胞的变化及其意义

目的 研究γ射线照射后C57小鼠骨髓中CD34^ 细胞的数量变化规律及其意义。方法 流式细胞仪测定CD34^ 细胞在骨髓有核细胞中的比例;Annexin V-FITCy试剂盒检测骨髓细胞的凋亡;细胞固定后PI染色测定细胞周期。结果 ①CD34^ 细胞在骨髓有核细胞中的比例随照射剂量的加大而降低,在5．5Gy照射后14d内小鼠CD34^ 细胞的减少表现为持续性;②小鼠照射后6h骨髓细胞凋亡率最高,以5．5Gy照射组最为明显;③5．5Gy照射后小鼠骨髓细胞周期紊乱。结论 γ射线损伤骨髓中的干祖细胞,造成骨髓中干祖细胞的数量减少,其途径之一是诱导骨髓细胞凋亡。     

Apoptotic cell death in erythrocytes of p53-deficient medaka (Oryzias latipes) after γ-irradiation

Purpose: Previous studies have examined the effects of γ-irradiation (γ-IR) on wild-type and p53 mutant Medaka (Oryzias latipes) 24?hours after irradiation and in the present work, apoptosis and alterations in erythrocytes of 4, 8 and 24?h and 14 days after gamma-ray irradiation were reported as genotoxic biomarkers of γ-irradiation.

Materials and methods: Sexually mature wild-type, WT (Hd-rR) and p53(?/?) adult female medaka (O. latipes) were exposed to 4?Gy dose of γ-IR and sampling were collected after 4, 8 and 24?h and 14 days.

Results: Apoptosis and morphological alterations were observed from 4?h after irradiation and remarkably increased 8?h after irradiation in the wild-type. Apoptotic cell death has been observed 8?h after irradiation most prominently but subtle in p53 mutant medaka. All these phenotypes were recovered 14 days after irradiation in both strains. Although no micronuclei were seen in any group, nuclear abnormalities were observed in red blood cells. Both apoptosis and morphological alterations in erythrocytes were decreased after 24 and 14 days after γ-irradiation.

Conclusions: We conclude that apoptosis and malformations caused by 4?Gy γ-irradiation in the erythrocytes of medaka fish occurs from 4–24?h and the initial response until 8?h was p53-dependent.     

抗辐射药物2,2-二甲基四氢噻唑及胱胺有机酸盐的研究

为了改善２，２－二甲基四氢噻唑盐酸盐（ＤＭＴＤ）的理化性质及提高辐射防护效价。方法合成了ＤＭＴＤ和胱胺的各种有机酸盐，对９．０３Ｇｙ６０Ｃｏγ射线一次全身照射的小鼠，照前给药，评价它们的辐射防护效果。结果大部分化合物具有不同程度的防护效果，其中ＤＭＴＤ酒石酸盐２５０ｍｇ／ｋｇ，照前一小时腹腔注射，存活率比单独照射对照组提高４０％；胱胺琥珀酸盐２５０ｍｇ／ｋｇ，照前１５分钟腹腔注射，存活率净增加７７．５％。结论胱胺琥珀酸盐的辐射防护效果显著，值得进一步研究     

Icariin protects against radiation-induced mortality and damage in vitro and in vivo

Abstract

Purpose: The present study aimed to investigate the potential protective effects of icariin both in vivo and in vitro, an active flavonoid glucoside derived from medicinal herb Epimedium, and its possible mechanisms against radiation-induced injury.

Methods: Male C57BL/6 mice were exposed to lethal dose (7?Gy) or sub-lethal dose (4?Gy) of whole body radiation by X-ray at a dose rate of ～0.55?Gy/min, and icariin was given three times at 24?h and 30?min before and 24?h after the irradiation. After irradiation, hematological, biochemical, and histological evaluations were performed. We further determined the effect of icariin on radiation-induced cytotoxicity and changes in apoptosis-related protein expression.

Results: Icariin enhanced the 30-day survival rates (20 and 40?mg/kg) in a dose-dependent manner, and protected the radiosensitive organs such as intestine and testis from the radiation damages. Moreover, hematopoietic damage by radiation was significantly decreased in icariin-treated mice as demonstrated by the increases in number of peripheral blood cells, bone marrow cells (1.7-fold), and spleen colony forming units (1.7-fold). In addition, icariin decreased the radiation-induced oxidative stress by modulating endogenous antioxidant levels. Subsequent in vitro studies showed that icariin effectively increased cell viability (1.4-fold) and suppressed the expression of apoptosis-related proteins after irradiation.

Conclusion: These results suggest that icariin has significant protective effects against radiation-induced damages partly through its anti-oxidative and anti-apoptotic properties.     

X射线对小鼠胸腺细胞凋亡的影响

采用荧光分光光度法对裂解ＤＮＡ进行定量，并用琼脂糖凝胶电泳法定性研究Ｘ射线全身照射后小鼠胸腺细胞凋亡。结果表明，４ＧｙＸ射线照后２小时胸腺细胞凋亡开始增加，于照后１４小时达峰值，尔后呈下降趋势。ＤＮＡ裂解率在照后２４小时降至１４小时的５０％，这可能是内环境中巨噬细胞吞噬凋亡小体所致。在照射后１４小时研究其剂量－效应关系发现，高剂量照射使ＤＮＡ裂解明显增多，形成１８０ｂｐ（ｂａｓｅｐａｉｒｓ）左右或其整倍数的ＤＮＡ断片，电泳呈现＂梯形图谱＂；而低剂量辐射可使ＤＮＡ裂解率降低。剂量－效应曲线呈Ｊ型。     

Anti-apoptotic effect of 3-aminobenzamide,an inhibitor of poly (ADP-ribose) polymerase,against multiple organ damage induced by gamma irradiation in rats

Purpose: This study aimed to investigate the effect of 3-aminobenzamide (3-AB) in doses of 5, 10 and 15?mg/kg on the inhibition of Poly (ADP-ribose) polymerase (PARP) when combined with ionizing radiation (IR).

Material and methods: Rats were treated intraperitonealy, one hour prior to irradiation at a dose level of 6 Gray (Gy) and were sacrificed 24?hours after irradiation. Control groups were run concurrently.

Results: IR led to an increase of thiobarbituric acid reactive substance (TBARS), nitrite as well as a decrease in total antioxidant capacity associated increase in myeloperoxidase (MPO) with the expression of cyclooxygenase-2 (COX-2). Moreover, IR caused an increase in serum lactate dehydrogenase (LDH) activity and cytosolyic Ca⁺² associated with an expression of Caspase-3 as well as a decline in complex-I activity and adenosine triphosphate (ATP) level. Pretreatment with 5 and 10?mg/kg of 3AB guarded against the changes in all the measured parameters, conversely the dose of 15?mg/kg showed no effect on the damage induced by irradiation in the selected tissues. Moreover, 3AB has a dose-dependent effect on viability of Vero cells.

Conclusion: The selected low doses of 3AB rather than the higher dose (15?mg/kg) protected against radiation-induced multiple organ damage.     

Attenuation of radiation-induced gastrointestinal damage by epidermal growth factor and bone marrow transplantation in mice

Purpose: We examined the effect of epidermal growth factor (EGF) and bone marrow transplantation (BMT) on gastrointestinal damage after high-dose irradiation of mice.

Material and methods: C57Black/6 mice were used. Two survival experiments were performed (12 and 13 Gy; ⁶⁰Co, 0.59–0.57 Gy/min). To evaluate BMT and EGF action, five groups were established – 0 Gy, 13 Gy, 13 Gy + EGF (at 2 mg/kg, first dose 24 h after irradiation and then every 48 h), 13 Gy + BMT (5 × 10⁶ cells from green fluorescent protein [GFP] syngenic mice, 4 h after irradiation), and 13 Gy + BMT + EGF. Survival data, blood cell counts, gastrointestine and liver parameters and GFP positive cell migration were measured.

Results: BMT and EGF (three doses, at 2 mg/kg, administered 1, 3 and 5 days after irradiation) significantly increased survival (13 Gy). In blood, progressive cytopenia was observed with BMT, EGF or their combination having no improving effect early after irradiation. In gastrointestinal system, BMT, EGF and their combination attenuated radiation-induced atrophy and increased regeneration during first week after irradiation with the combination being most effective. Signs of systemic inflammatory reaction were observed 30 days after irradiation.

Conclusions: Our data indicate that BMT together with EGF is a promising strategy in the treatment of high-dose whole-body irradiation damage.     

电离辐射对松果腺细胞功能的影响

目的研究电离辐射对松果腺细胞凋亡、cAMP和褪黑素(MLT)含量的变化规律及特点。方法采用流式细胞术检测松果腺细胞凋亡。采用放免分析法检测松果腺细胞中cAMP含量。采用高效液相色谱分析法检测松果腺细胞中MLT含量。结果小鼠受0．5～6Cy X射线全身照射12h，随剂量增加松果腺细胞凋亡百分率增加；照射后24h，随剂量增加松果腺细胞中cAMP含量降低。小鼠受1～6Cy照射后12h，随剂量增加松果腺细胞合成和分泌MLT功能减弱。结论高剂量电离辐射对松果腺细胞功能有抑制作用．     

西咪替丁对急性照射小鼠存活率及造血系统改变的影响

目的 观察西咪替丁对急性照射小鼠存活率及造血系统改变的影响.方法 采用137Cs γ射线全身照射小鼠,两次实验的照射剂量分别为6.0Gy和8.0Gy,剂量率均为1.01Gy/min.每次实验取健康雄性C57BL/6小鼠60只,按体重随机分为空白对照组?模型对照组?阳性药组(523)及33.3?100?300mg/kg西咪替丁组,每组10只.西咪替丁各剂量组于照射前6d灌胃给药,每天1次,照射后5h给药1次;阳性药组于照射前1d灌胃给药1次,照射后5h给药1次.检测8.0Gy照射后30d小鼠存活率,以及6.0Gy照射后30d小鼠外周血象?骨髓DNA含量和骨髓嗜多染红细胞微核率.结果8.0Gy照射后,模型对照组小鼠于第21天全部死亡,西咪替丁低?中?高剂量组30d存活率分别为50%?20%和30%;6.0Gy照射后第30天,与空白对照组比较,各照射组小鼠外周血白细胞明显降低(P<0.01),骨髓嗜多染红细胞微核率明显升高(P<0.05),骨髓DNA含量明显降低(P<0.05);与模型对照组比较,西咪替丁高剂量组外周血白细胞明显升高(P<0.01),西咪替丁各剂量组骨髓DNA含量明显升高(P<0.01,P<0.05),而骨髓嗜多染红细胞微核率明显降低(P<0.01,P<0.05)并趋于正常.结论 西咪替丁能提高急性照射小鼠30d存活率,且对其造血系统有较好的保护作用.     

低剂量辐射诱导小鼠胸腺细胞及其亚组的适应性反应

目的研究低剂量辐射预先照射以及随后大剂量照射后小鼠胸腺细胞Ｔ细胞受体（ＴＣＲ）、ＣＤ３、ＣＤ４和ＣＤ８分子表达的变化。方法ＴＣＲ、ＣＤ３表达采用间接荧光流式细胞术检测,ＣＤ４、ＣＤ８表达采用双参数直接免疫荧光流式细胞术检测。结果实验结果表明：单纯１５ＧｙＸ射线全身照射后ＴＣＲ,ＣＤ３阳性细胞数以及ＣＤ４－Ｄ８－,ＣＤ４＋ＣＤ８＋,ＣＤ４＋ＣＤ８－和ＣＤ４－ＣＤ８＋细胞数明显减少,当１５ＧｙＸ射线全身照射前６小时预先照射００７５Ｇｙ时,可明显减轻其后１５Ｇｙ照射对ＴＣＲ＋,ＣＤ３＋,ＣＤ４＋ＣＤ８＋,ＣＤ４＋ＣＤ８－和ＣＤ４－ＣＤ８＋的损伤作用。表现为各亚组细胞数显著高于单纯１５Ｇｙ照射组。ＣＤ４－ＣＤ８－亚组的细胞数无明显变化。结论００７５ＧｙＸ射线全身照射能够诱导胸腺细胞ＴＣＲ＋,ＣＤ３＋,ＣＤ４＋ＣＤ８＋,ＣＤ４＋ＣＤ８－和ＣＤ４－ＣＤ８＋亚组细胞的适应性反应。     

党参乙醇总提物的抗辐射作用研究

目的探讨党参乙醇总提物（total ethanol extract from Codonopsis pilosula,TEC）对60Coγ射线损伤的防护及其治疗作用。方法 70只小鼠受60Coγ射线7.5 Gy照射前后,实验组用2种不同浓度的TEC灌胃,照射对照组小鼠用蒸馏水灌胃,观察不同处理组小鼠的存活率及血像变化情况,在此基础上优选出最佳保护方式;另外对40只小鼠给予8.0 Gy致死剂量照射,观察TEC对小鼠的辐射保护作用。结果 （1）致伤前预防给药,两个剂量TEC均明显提高了30 d存活率以及外周血白细胞计数（WBC）和血小板计数（PLT）;（2）致伤后给药两个剂量均没有显示出显著的治疗效果;（3）给予8.0 Gy致死剂量照射,TEC较照射对照组提高存活率50%,有统计学差异（P〈0.05）。结论 TEC具有较强的辐射预防作用,能显著提高受60Coγ射线致死剂量照射小鼠的存活率,降低辐射对小鼠外周血WBC和PLT的损伤作用。