This study investigated the effect of predation induced stress during pregnancy on demasculinization of sexual behavior for male offspring in root voles Microtus oeconomus . Male offspring were randomly assigned to fo...This study investigated the effect of predation induced stress during pregnancy on demasculinization of sexual behavior for male offspring in root voles Microtus oeconomus . Male offspring were randomly assigned to four groups. Two groups were stressed by predation and restricted food, respectively, in the prenatal period. One group was stressed by predation after weaning. The remaining was the control group. During adulthood, male offspring were tested for sexual behavior and anogential distance. The results showed that prenatal stress with predation induced a major impairment of male sexual behavior and anogential distance. The group with restricted food displayed a minor impairment in male sexual behavior and anogential distance. The weaning stress showed no marked differences in male sexual behavior and anogential distance when compared to controls. These results demonstrated that predation induced prenatal stress, together with the stress with restricted food in the mothers induced the behavioral and the morphological demasculinization of their male offspring. The effect of demasculinization occurred only during the critical phase that caused sexual differentiation of the male embryonic hypothalamus.展开更多
文摘This study investigated the effect of predation induced stress during pregnancy on demasculinization of sexual behavior for male offspring in root voles Microtus oeconomus . Male offspring were randomly assigned to four groups. Two groups were stressed by predation and restricted food, respectively, in the prenatal period. One group was stressed by predation after weaning. The remaining was the control group. During adulthood, male offspring were tested for sexual behavior and anogential distance. The results showed that prenatal stress with predation induced a major impairment of male sexual behavior and anogential distance. The group with restricted food displayed a minor impairment in male sexual behavior and anogential distance. The weaning stress showed no marked differences in male sexual behavior and anogential distance when compared to controls. These results demonstrated that predation induced prenatal stress, together with the stress with restricted food in the mothers induced the behavioral and the morphological demasculinization of their male offspring. The effect of demasculinization occurred only during the critical phase that caused sexual differentiation of the male embryonic hypothalamus.
文摘目的:探讨2-3-7-8四氯二苯并二噁英(2-3-7-8 Tetrachlorodibenzo-p-Dioxin,TCDD)宫内暴露对雄性子代生殖毒性的影响及机制。方法:成功交配后,将母鼠随机分组。高剂量组(0.5μg/kg)、低剂量组(0.1μg/kg)和溶剂对照组,每组各6只,TCDD组及对照组于孕8~14 d(gestation day 8-14,GD8-14)采用灌胃方式分别给予TCDD及玉米油处理。孕鼠自然分娩,测量雄性仔鼠肛门至生殖器的距离(anal to genital distance,AGD);计算睾丸的脏器系数;利用精子质量分析仪对仔鼠精子的质量及数量进行分析测定;酶联免疫吸附法对雄性子代血清睾酮(testosterone,T)水平进行测定;测定凋亡相关蛋白Bax、Bcl2、Caspase-3的表达水平。结果:0.1μg/kg组、0.5μg/kg组仔鼠与对照组仔鼠相比,AGD[(1.49±0.04)cm、(1.32±0.01)cm和(1.21±0.02)cm]有所缩短(P=0.000),精子数目[(72.33±4.46)×10^6个/mL、(63.67±3.44)×10^6个/mL、(45.33±5.47)×10^6个/mL]与精子活率[(78.53±1.26)%、(64.40±3.14)%、(53.87±3.65)%]明显降低,精子畸形率[(2.17±0.75)%、(4.83±0.75)%、(8.00±1.10)%]升高(P=0.000),血清中T水平[(2.68±0.06)ng/mL、(2.38±0.08)ng/mL和(2.10±0.09)ng/mL]明显下降(P=0.000),差异均有统计学意义,0.5μg/kg TCDD组雄性仔鼠的睾丸质量(P=0.001)和睾丸脏器系数(P=0.004)降低的差异有统计学意义;睾丸组织细胞Bax蛋白相对表达量(0.836±0.004、1.185±0.004、1.414±0.001)随染毒剂量的递增而上升(P=0.000),Bcl-2(1.368±0.053、1.108±0.040、0.751±0.022)则相反(P=0.001),同时,0.5μg/kg TCDD染毒组Pro-Caspase-3蛋白表达明显降低,但CleavedCaspase-3蛋白表达明显增加(P=0.000)。结论:宫内暴露TCDD可使雄性仔鼠出现雌性化特征,影响雄性仔鼠生育能力,对雄性子代具有生殖毒性,其机制可能与仔鼠睾丸组织细胞增殖-凋亡失衡和细胞凋亡的线粒体通路被激活有关。
