發(fā)布時間：2018-04-01 22:02

  本文選題：鎘　切入點：神經(jīng)管畸形　出處：《安徽醫(yī)科大學(xué)》2017年碩士論文

【摘要】：目的:此前的研究發(fā)現(xiàn)孕鼠在孕期GD9暴露鎘可致胎鼠前肢缺趾畸形和尾部畸形,本次實驗研究在胎兒神經(jīng)管形成期對孕鼠進行鎘暴露是否會導(dǎo)致胎鼠神經(jīng)管畸形并初步探討其部分機制。方法:本次實驗主要包括以下三個實驗:實驗一:鎘致胎鼠神經(jīng)管畸形模型:36只ICR小鼠在受孕第8(GD8)天按體重隨機平均分為三組,于GD8天8:00a.m-9:00a.m通過腹腔注射分別給予0、2.5、5mg/kg的Cd Cl_2。受孕期間三天稱量一次孕鼠體重,每天記錄孕鼠飲食飲水量。GD18天進行取材,摘眼球法收集孕鼠血液,頸椎脫臼法處死并剖殺所有孕鼠,記錄活胎數(shù)、死胎數(shù)、畸形胎鼠數(shù)和吸收胎數(shù),稱量活胎體重和胎盤重量,留取胎盤作病理切片觀察HE染色。實驗二:研究孕鼠鎘暴露后對葉酸轉(zhuǎn)運的影響:24只ICR小鼠按體重在受孕第8(GD8)天按體重隨機分為兩組(對照組與鎘處理組),鎘處理組于GD8天8:00a.m-9:00a.m單次腹腔注射5mg/kg的Cd Cl_2,對照組給予生理鹽水處理。24h后剖殺孕鼠,摘眼球法收集孕鼠血液,取胚胎和胎盤。血液室溫靜置2h左右3000轉(zhuǎn)離心10min留血清和胚胎一起-80℃保存用于檢測葉酸含量。實驗三:研究孕鼠鎘暴露后對胎盤葉酸轉(zhuǎn)運泵的影響:48只ICR小鼠按體重在受孕第8(GD8)天按體重隨機分為8組。其中,鎘處理組于GD8天8:00a.m-9:00a.m單次腹腔注射5mg/kg的Cd Cl_2,對照組給予生理鹽水處理。鎘處理組孕鼠于鎘處理后不同時間點剖殺(2h、12h、24h、48h、72h),對照組于0h、24h、48h、72h進行剖殺。摘眼球法收集孕鼠血液,取胎盤做RT-PCR和Western Blotting實驗檢測胎盤葉酸轉(zhuǎn)運泵水平。結(jié)果:孕鼠孕期第8天暴露鎘可致胎鼠神經(jīng)管畸形。其中2.5mg/kg鎘處理組的窩神經(jīng)管畸形率為33.3%(4/12),平均胎鼠神經(jīng)管畸形率為3.6%,5mg/kg鎘處理組的窩神經(jīng)管畸形率高達75%(9/12),平均胎鼠神經(jīng)管畸形率為20.0%,同時鎘暴露可致胎鼠體重減少,母體孕期鎘暴露對胎鼠體重的減少呈劑量反應(yīng)關(guān)系(劑量越高,胎鼠體重越輕)。此外,鎘暴露也會導(dǎo)致胎鼠身長明顯減少;并且孕鼠孕期鎘暴露會損害胎盤的發(fā)育,對胎盤重量的減少呈劑量反應(yīng)關(guān)系(劑量越高,胎盤重量越輕)。相應(yīng)的鎘暴露也會導(dǎo)致胎盤直徑明顯減少,對胎盤的病理HE染色發(fā)現(xiàn),鎘處理組的胎盤迷路層血管明顯減少。我們進一步檢測了母體血清和胎鼠的葉酸水平,發(fā)現(xiàn)鎘處理組的胎盤葉酸水平明顯下降;此后,我們檢測了胎盤的葉酸轉(zhuǎn)運泵Pcft,Frα和Rfc1,發(fā)現(xiàn)Pcft的m RNA水平在鎘處理2h后就顯著下調(diào),并且在鎘處理24h后依舊保持下降狀態(tài),我們通過Weatern Blotting實驗在蛋白水平也得到了驗證。結(jié)論:孕鼠妊娠期在胎兒器官形成階段進行鎘暴露,會下調(diào)胎盤的葉酸轉(zhuǎn)運泵的表達,從而干擾葉酸由母體循環(huán)進入胎兒體內(nèi)繼而誘發(fā)胎鼠神經(jīng)管畸形。
[Abstract]:Objective: previous studies have found that exposure to cadmium in GD9 during pregnancy can lead to deformity of forelimb and tail of fetal mice. This experiment was conducted to study whether exposure to cadmium in fetal rats during fetal neural tube formation would lead to fetal neural tube malformation and explore some of its mechanisms. Methods: this experiment mainly includes the following three experiments: experiment 1: cadmium induced by cadmium. Fetal rat neural tube malformation model: 36 ICR mice were randomly divided into three groups according to their body weight on the 8th day of conception. On the day of GD8, 8:00a.m-9:00a.m was injected intraperitoneally with 0.5 mg / kg of CD Cl2.The body weight of pregnant rats was measured once every three days during pregnancy, the diet and drinking quantity of pregnant rats were recorded every day for 18 days, the blood of pregnant rats was collected by eyeball extraction, the cervical vertebrae dislocated and all pregnant rats were killed and all the pregnant rats were killed. The number of live fetus, the number of dead fetus, the number of malformed fetus and the number of absorbed fetus, the weight of live fetus and placenta weight were recorded. The effect of cadmium exposure on folic acid transport in pregnant mice was studied. Experiment 2: 24 ICR mice were randomly divided into two groups according to their body weight according to their body weight on the 8th day of gestation (control group and cadmium treatment group). The rats in the control group were treated with normal saline for 24 hours. The pregnant rats were killed by single intraperitoneal injection of CDCl2 from 8:00a.m-9:00a.m on the day of GD8, and the rats in the control group were treated with normal saline for 24 hours. The blood of pregnant mice was collected by eyeball extraction. Fetuses and placentas were taken. Blood was stored at room temperature for 2 hours or so for 3000 rpm centrifugation 10min to preserve serum and embryo together at -80 鈩，

本文編號：1697463