香烟烟雾对雌鼠卵母细胞氧化损伤及发育潜能的影响

Effects of cigarette smoke on the oxidative damage of mice oocytes and developmental potential

目的研究香烟烟雾暴露对雌鼠卵母细胞的氧化应激水平及其发育潜能的影响。方法将96只SPF级6周龄ICR雌鼠按照体重相近原则随机分为对照组、低剂量组、中剂量组和高剂量组,每组24只,实验组置于点燃1支香烟的染毒柜中,染毒柜容积分别为60、32和23 L,对照组正常饲养,每天2次,每次1 h,连续4周。每天称重并记录,绘制体重变化曲线;利用试剂盒检测卵巢组织超氧化物歧化酶(superoxide dismutase,SOD)和谷胱甘肽过氧化物酶(glutathione peroxidase,GPX)活性水平;通过组织切片、间接免疫荧光及体外成熟等技术分别检测各组卵巢脏器系数、卵母细胞活性氧(reactive oxygen species,ROS)水平及第一极体率等指标。两组均值的比较采用t检验,多组均值之间的比较采用单因素方差分析,P<0.05表示差异具有统计学意义。结果与对照组比较,处理组小鼠体重增长明显减慢,高剂量组体重增量仅为1.05%±0.41%;卵巢脏器系数、卵巢组织SOD、GPX活性及产仔量(高剂量组降至5.20%±1.48%)均明显下降;卵母细胞中ROS水平明显升高,卵母细胞体外成熟第一极体率降低,高剂量组降至49.34%±5.78%,差异均具有统计学意义(P<0.05)。结论香烟烟雾暴露可引起小鼠卵巢脏器系数、SOD、GPX活性水平下降,卵母细胞内ROS含量增高,第一极体率及产仔量的下降。

OBJECTIVE To study the effects of cigarette smoke on the oxidative damage of mice oocytes and developmental potential.METHODS A total of 96 SPF grade 6-week-old ICR female mice were randomly divided into control group,low- dose group,middle-dose group and high-dose group according to the principle of similar body weight.Twenty-four mice in each group were placed in a cigarette-lighting containers with the volume of 60,32 and 23 L respectively.The control group was fed normally twice a day for 1 hour for 4 weeks.Weight and record daily,draw weight change curve;use kit to detect the activity of superoxide dismutase (SOD)and glutathione peroxidase (GPX) in ovarian tissue;use tissue section,indirect immunofluorescence and in vitro maturation technology to detect the activity of each group.The ovarian organ index,the level of reactive oxygen species (ROS)in oocyte and the first polar body rate were measured.The t test was used to compare the mean values of the two groups,and one-way ANOVA was used to compare the mean values of the multiple groups.RESULTS Compared with the control group,the weight gain of mice in the treatment group was significantly slower (the weight gain in the high dose group was only 1.05%+0.41%).The ovarian organ index, SOD and GPX activity in the ovarian tissue and litter size (the high dose group was reduced to 5.20%±1.48%)were significantly decreased.The ROS level in oocyte was significantly increased,and ooeyte maturation in vitro was the first.The polar body rate decreased (high dose group decreased to 49.34%±+5.78%),and the difference was statistically significant (P <0.05).CONCLUSION Cigarette smoke exposure in mice can cause the decrease of ovarian organ index,SOD and GPX activity,the increase of ROS content in oocyte,the decrease of first polar body rate and litter size.