^125I,^131I诱发小鼠精子畸形发生率比较

本文选用 ICR 雄性小鼠,经腹腔分别注射不同剂量的~(125)I 及~(131)I,观察并比较它们对小鼠精子畸形发生率的影响及染毒后睾丸中放射性活度的变化。实验结果表明:(1)~(125)I 染毒后4—5周,0、185、370和555 kBq 各组精子畸形发生率分别为9.00‰、9.57‰、11.6‰及13.9‰;~(131)I 染毒后4—5周,上述各组精子畸形发生率分别为8.50‰、12.5‰、14.7‰和15.5‰;在相同注入量下,~(125)I 与~(131)I 诱发小鼠精子畸形发生率的差异各组均不显著(X~2检验,p>0.05)。(2)~(125)I、~(131)I 染毒后2h 至7天内,两者在睾丸中的放射性活度及变化规律相似,即在染毒后2h 达最高值,每克睾丸中~(125)I 和~(131)I 的放射性活度分别占初始注入量(370 kBq)的0.72％和0.50％,然后迅速下降,至一周时,仅分别占初始注入量的0.035％和0.011％。     

60Co γ射线8.0 Gy剂量诱导小鼠十二指肠恢复期损伤

采用⁶⁰Co γ射线对小鼠腹腔进行一次性照射,照射剂量为8.0 Gy,在照射后第15 d的恢复期,观察小鼠十二指肠的病理变化,分析BCL-2和TGF-β蛋白质表达水平。结果表明:(1) 与对照组相比,照射组十二指肠病理出现绒毛萎缩、变短或脱落,严重者可见肠粘膜上皮广泛性坏死剥脱;(2) 照射组BCL-2蛋白质表达水平下降,TGF-β蛋白质表达水平升高。结果说明,该照射方法下恢复期时放射性肠损伤仍然存在。     

微波对小鼠睾丸染色体的影响

本文使用2450MHz 连续微波照射 C_(57)BL 小鼠,观察生殖细胞染色体畸变。在功率密度约20、30及37mW/cm~2三种辐射强度下,睾丸周围的温度分別达37.5℃左右、38—39℃及40℃左右。最低辐射强度组动物的染色体畸变与对照组无差异。在其他两个辐射组,可见到细胞染色体畸变率增高,尤以高强度辐射组为明显。精原细胞的细胞染色体畸变率分别达12.16%及5.45%(对照组为1.26%);初级精母细胞第一次减数分裂的细胞染色体畸变率分别达9.31%及5.28%(对照组为2.56%)。畸变类型主要为染色单体断片、断裂,个别细胞的染色体或个別染色体出现粉碎化。     

小肠RNA对小鼠电离辐射肠道损伤修复的差异基因表达的研究

为从基因水平探讨小肠糖核酸,促进小鼠电离辐射肠道操作修复的机理,采用随机分组法把９０只小鼠分成４组,建立辐射后给予４０μｇＲＮＡ治疗的实验组与０．４ｍＬ生理盐水治疗的对照组模型,分别于照射后６、１２、２４ｈ,４ｄ和８ｄ采集小肠空肠段标本,动用消减杂交基础上的ＬＤ－ＰＣＲ技术,分离实验组与对照组之间的差异表达基因。结果表明：实验组与对照组６、１２、２４ｈ,４ｄ和８ｄ的克隆新表达基因数分别为１８、２２     

细菌型豆豉激酶对小鼠尾静脉血栓模型的保护作用研究

在小白鼠腰背部皮下注射1%角叉菜胶溶液诱发小鼠尾静脉血栓,通过饲喂不同剂量的细菌型豆豉激酶来研究其在动物体内的溶栓作用。实验结果发现,豆豉激酶对角叉菜胶造成的小鼠血栓形成呈现一定的剂量效应趋势,随着灌胃剂量的增大,血栓形成相对长度减小。这说明豆豉激酶对血栓形成具有预防作用。     

Antiobese and hypocholesterolaemic effects of an Adenophora triphylla extract in HepG2 cells and high fat diet-induced obese mice

The ethyl acetate extract from Adenophora triphylla root (ATea) had strong antioxidant effect. We hypothesised that a high fat (HF) diet might induce oxidative stress and so, dietary antioxidant may have beneficial effects on hypercholesterolaemia, but the underlying mechanisms involved are not fully understood. To test this hypothesis, C57BL/6 mice were fed with HF diet for 9 weeks. In the last 4 weeks, the HF diet was supplemented with 0, 25 or 75 mg/kg ATea. ATea decreased body weight gain and both ATea doses significantly reduced the plasma and hepatic cholesterol levels of the obese mice. Analysis of the hepatic expression of proteins known to play important roles in cholesterol metabolism indicated that ATea significantly enhanced low density lipoprotein receptor (LDL receptor) and cholesterol 7α-hydroxylase (CYP7A1) expression but inhibited the 3-hydroxy-3-methylglutaryl–CoA reductase (HMG–CoA reductase) expression in HepG2 cells and mice. No mutagenic activity was observed at high doses of ATea.     

Male Urinary Chemosignals Differentially Affect Aggressive Behavior in Male Mice

Chemical signals modulate aggressive behavior in mice. For example, male urinary cues enhance aggression against other adults: a resident mouse attacks a male but not a castrated intruder, unless it is anointed with male urine. Our purpose was to understand whether molecules excreted with urine also act as aggression triggers in a different context. Therefore, the effect of urine, or molecules purified from urine, voided by different animals (males or females), was tested on the aggression of male mice against pups. Latency to the first attack, percentage of pups receiving the first attack, and percentage of attacked pups after 5 and 15 min were recorded. At variance with intermale aggression, male urinary chemosignals sprayed on pups reduced infanticide, while female urine did not. Male urine also delayed infanticide when compared to female urine. Pups anointed with low molecular weight dialyzed urine and with the high molecular weight protein fraction were attacked later than controls. Pups anointed with Major Urinary Proteins (MUPs) also were attacked later. The volatiles retained by MUPs act in the same way as adult male urine. MUPs and their ligands did not modify biting of food items. The results show that mice do not perceive male chemosignals as compulsory aggression triggers but rather can consistently and differentially shape their behavior in response to the same molecules according to different contextual events.     

红花籽油的抗氧化功能研究

针对红花籽油的抗氧化功能进行研究,通过其对1,1-二苯基-2-三硝基苯肼自由基、超氧阴离子自由基、羟自由基的清除能力以及还原能力的测定,进行体外抗氧化试验;在体内抗氧化试验中,将60只雄性昆明种小鼠分为6组,其中阴性对照组和模型对照组给予蒸馏水,阳性对照组每日灌胃0.02 g/kg bw VE,3个试验组每日分别灌胃0.625、1.25、2.5 g/kg bw红花籽油,连续灌胃30 d。末次灌胃后,除阴性对照组外,模型对照组、阳性对照组和3个试验组均给予50%乙醇12 m L/kg bw造过氧化损伤,6 h后取样测定血清和肝脏中超氧化物歧化酶、谷胱甘肽过氧化物酶、还原型谷胱甘肽、丙二醛和蛋白质羰基的含量。结果表明:在体外抗氧化试验中,红花籽油对化学体系产生的自由基具有较强清除能力,同时还具有还原能力;在体内抗氧化试验中,红花籽油能显著提高血清和肝脏SOD、GSH-Px、GSH水平,降低MDA和PC含量,对乙醇所致机体过氧化性损伤起保护作用,以0.625 g/kg bw剂量效果最佳。结论:红花籽油具有抗氧化作用,但不能过量摄入。     

保健食品促进排铅模型小鼠饮水染铅剂量及检测指标的探讨

为探讨保健食品促进排铅作用动物模型饮水染毒的适宜剂量，给小鼠自由饮用Pb^2 浓度为163．9、546．2、l638．7mg／L的醋酸铅溶液30d，每周记录饮用量，周末称重，估算实际铅摄入剂量。实验末取血、肝、脑、肾、股骨，石墨炉原子吸收分光光度法测定全血和组织铅含量。结果显示，163．9、546．2、l638，7mg Pb^2 ／L剂量组小鼠实际铅摄入剂量分别为27．9、86．6、169．4mg／kg BW，546．2、1638．7mg Pb^2 ／L剂量组小鼠体重增长较对照组显著减少，食物利用率也明显降低；各剂量组小鼠全血、肝、肾、股骨铅及546．2、1638．7mg Pb^2 ／L剂量组小鼠脑铅含量显著升高。建议以546．2mg Pb^2 ／L作为保健食品促进排铅作用饮水染毒的造模剂量；除骨铅外，建议增测肾脏、脑组织内的铅、锌、铜含量及骨骼内的钙含量。