目的 建立F344纯系大鼠低硒动物模型,观察低硒对子代仔鼠神经行为发育和空间学习记忆能力的影响。方法 以纯系F344大鼠为实验对象。采用人工丰合成饲料(低硒组饲料硒含量〈0.01mg/kg,补硒对照组饲料中硒含量为0.1~0.3mg/kg)建立低硒大鼠模型,观测子一代仔鼠哺乳期的生长体重变化、生长发育生理学指标和神经反射指标,并采用开场实验、Morris水迷宫实验检测其行为活动和空同学习记忆能力。结果 (1)低硒组大鼠尾血GSH-Px活性极其显著地低于对照组(P〈0.001)。(2)低硒组仔鼠的出生体重和哺乳期神经发育不同时间点体重明显低于对照组。(3)仔鼠出生后第4天平面翻正和悬崖回避、第10天听觉惊愕反射实验中,低硒组评分均低于对照组(P〈0.05),但在第7天平面翻正、悬崖回避和第11天后的听觉惊愕反射实验以及第12、14天前肢悬挂、后肢行走能力实验中,两组仔鼠结果差异无统计学意义(P〉0.05)。(4)开场实验中:低硒组雄仔鼠在中央格停留时间、穿行格数较对照组明显减少(P〈0.05)。(5)Morris水迷宫实验:①低硒组仔鼠第4、5天的定位航行实验中,平均潜伏期比对照组明显延长(P〈0.05);在第6、9时间段的直线式搜索方式也较对照组减少(P〈0.05);②低硒组在空间探索实验中,原站台象限活动时间较对照组减少(P〈0.05)。结论 成功利用纯系F344大鼠建立了低硒动物模型,母代长期硒缺乏导致了子一代F344仔鼠出生体重减低、生后体格发育和神经行为发育的迟缓,雄性仔鼠对新异环境中的适应能力减弱,并且导致了子代仔鼠空间学习和记忆能力能力的减弱。
Objective To establish the selenium (Se) deficient animal model on F344 inbred line rats and observe the effects of a long-term Se-deficieney on the offspring' s neuro-behavior, abilities of learning and memory. Methods Feeding F344 inbred line rats on Se-deficient diet to establish Se-deficient animal model. For the offspring, the body weight, physiological indexes nervous reflections for growth and development were monitored during the early postnatal period, Results The Se-deficient diet contained less than O.Olnig/kg and the glutathione peroxidase(GSH-Px) activity in blood of the Se-defieient group rats is lower than the Se-normal group after feeding on Se-deficient diet for 4 weeks. For the offspring, the birth weight and the body weight of Se-defleient group were obviously lower than the Se-normal group before weaning. Se-deficient offspring rats differed from Se-normal controls in lower scores in surface righting reflex (RR) test at postnatal 4th day after delivery, cliff avoidance test at postnatal 7th day and auditory acuity trial at postnatal 10th day respectively. But these differences disappear after a few days in the same tests. In addition, no significant differences between two groups in suspending test and walking ability test at postnatal 12th and 14th day. In open field test, Sedeficient male offspring stayed less time in the middle grid and moved less. In Morris water maze test, the Se-deficient offspring spent more time to find the hidden platform at the 6th and 9th training tests in the place navigation trial. Furthermore, the Se-deficicnt group spent less time in target quadrant when giving the spatial probe trial. Conclusion A Se-deficient animal model have been established on F344 inbred line rats successfully. A long-term Se deficiency could retard the development of the offspring in uterus and after delivery. Se deficiency also decreased the offspring' s abilities of spatial learning and memory in Morris water maze test and resulted in the male offspring' s to new stimu