胎儿生长受限的关键期及其影响子代学习记忆的行为学研究

目的 探讨腹腔注射更生霉素和被动吸烟两种因素分别作用于不同孕期时诱发胎儿生长受限(fetal growth restriction,FGR)的时相特点及FGR对子代学习记忆力的影响;观察FGR子鼠体重增长特点. 方法 腹腔注射更牛霉素和被动吸烟两种方法建立大鼠FGR动物模型;Morris水迷宫检测FGR子代不同发育期空间学习记忆能力. 结果 两种方法均成功建立FGR动物模型,其FGR发病率分别为53.47%和35.53%,和对照组比较均有统计学意义(P＜0.05).妊娠早、中、晚期分别给孕鼠腹腔注射更生霉索,FGR发病率分别为:26.2%、47.7%、46.5%,中期和晚期比较无显著性差异,中、晚期和早期有显著性差异;妊娠早、中、晚期分别给孕鼠被动吸烟,FGR发病率分别为:20.9%、40%、45.7%,中期和早期、晚期比较均有显著性差异,早期和晚期比较无显著性差异.水迷宫实验中,FGR子鼠寻找站台所需时间明显长于对照组;定位航行时FGR子代通过站台区的次数明显少于对照组.FGR子鼠生后体重增长速度比对照组快,但体重始终未明显超过对照组. 结论 对妊娠不同时期的大鼠给予被动吸烟或腹腔注射更生霉素均可建立FGR动物模型.妊娠中、晚期是诱发FGR的关键期.FGR子代学习记忆能力均受到不同程度损害.FGR子代存在体重追赶现象.

Prenatal critical period for fetal growth restriction and the effect of FGR on learning and memorizing ability in rats' offsprigs

Objective To investigate the characteristics of fetal growth restriction(FGR)induced by intraperitoneally injection of Actinomycin D to pregnant rats or passive smoking of pregnant rats,to explore the effect of FGR on learning and memorizing ability of the offsprings involved and to observe the weight gaining of FGR offsprings.Methods FGR animal models were successfully established by both methods.Morris Water Escape Task was used to evaluate the search behavior of FGR offsprings and their spatial rememberance at different stages.Results The incidences of induced FGR were 53.47%(Actinomycin D)and 35.53%(passive smoking)respectively,and both were apparently higher than that of the control(P＜0.05).The incidences of FGR were 26.2%,47.7%and 46.5% respectively when Actinomycin D wasinjected at early,mid and late trimester.No difference was found in the incidence of FGR between the mid and late trimester(P＞0.05),but higher incidence of FGR was shown in mid and late trimester compared with the early trimester(P＜0.05).For the passive smoking pregnant rats at early,mid and late trimester,the incidences of FGR were 20.9%,40% and 45.7%.Significant difference was shown between the mid andearly late trimester(P＜0.05).During the Morris test,the progenies in FGR group spent more times in finding the platfom than those of the control,and more occasionally did they get through the area in which the platform was placed.Progenies in FGR group grew more quickly than those of the control,however,thebody weight of FGR progenies had never outweighted that of the control.Conclusions FGR animal model can be successfully established at any trimester in pregnant rats by either of the methods.The mid and late trimesters are the critical time for inducing FGR.Learning and memorizing ability of FGR offsprings is impaired to some extent.There is a postnatal careh-up growth in FGR offsprings.