Assessing Adverse Effects of Aroclor 1254 on Perinatally Exposed Rat Offspring

To assess the neurotoxic effects and redoxresponses of Aroclor 1254 （A1254） on perinatallyexposed rat offspring, A1254 was administered bygavage from gestational day （GD） 6 to postnatal day（PND） 21. Neurobehavioral development,antioxidant enzyme activities, lipid peroxidation（LPO）, nitric oxide （NO）, and NO synthase （NOS）levels were analyzed in the offspring.Neurobehavioral development analysis revealeddelayed appearance of the righting reflex, negativegeotaxis, and cliff drop test responses in A1254exposed group. Developmental A1254 exposurealso caused oxidative stress in the brain of PND 22offspring via reductions in the activity of SOD andGSH-Px, and by promoting a rise in the levels of NOand NOS.

Effects of High Fluoride and Low Iodine on Thyroid Function in Offspring Rats

Thirty-two Wistar rats were divided randomly into four groups of eight with six females and two males in each group. The rats were exposed to high fluoride drinking water （45 mg F-L^-1 from 100 mg NaF L-1）, low dietary iodine （0.0855 mg kg-1）, or both together in order to assess the effects of these three regimens on the thyroid function of the offspring rats. After the animal model was established, the offspring rats were bred and 10-, 20-, 30-, 60-, and 90-d-old rats were used for the experiment. The treatments for the offspring rats were the same as those of their parents. In comparison with control rats, the relative thyroid glands were changed by three regimens, but the mean values of thyroid weight in the experimental groups saw no marked difference. Serum TT3 levels were increased in all stages in the low iodine （LI） group. In the high fluoride （HiF） group, increase in TT3 levels was observed except in 20-d-old rats. Decrease in TT3 at 20- and 90-d and increase in TT3 at 30- and 60-d were found in HiF＋LI group. Serum TT4 levels first saw an increase, and then dropped in the LI and HiF＋LI group. However, an increase in TT4 was found in the HiF group. The levels of TSH in serum rocketed at d 20, and then dropped in the next stages in experimental groups. The results suggested that thyroid disorder could be induced by high flroride in drinking water, low iodine diet, or both of them. Exposure time to fluoride or low iodine diet was one of the important factors that fluoride can induce the development of thyroid dyfunction.

Maternal Separation Affects Mothers’ Affective and Reproductive Behaviors as Well as Second Offspring’s Emotionality

Daily separation of rat pups from their mothers while the preweaning period has an impact on behavior and stress response of pups. We hypothesized that maternal separation may create a depression-like state in mother rats from which we separate the rat pups and decrease their reproductive function and fertility. Also, we aimed to evaluate the transmission degree of depression and anxiety across generations. Females aged 3 months were divided in two groups of 10 rats each. After a first mating and a first parturition, we conducted maternal separation 3 h during 22 days for the experienced group while the control group mothers kept their pups. At 4 months of age, females underwent behavioral tests and a second mating. Second generation’s pups were also subjected to behavioral tests. Behavioral tests showed that mothers which experienced separation were more depressive and anxious than control ones, also they had a lower litter size. Rats pups of the second generation whose mothers experienced maternal separation also revealed behavior changes akin to depression and anxiety. Thus, maternal separation causes depressive and anxious-likestates on mother rats which experienced separation and has an impact on their litter size. Also, consequences of maternal separation seem to last throughout generations.

Effect of Perinatal Bisphenol A Exposure on Serum Lipids and Lipid Enzymes in Offspring Rats of Different Sex

Rats were exposed to1 or 10 μg/mL bisphenol A （BPA） in water during pregnancy and lactation. Offspring rats were given normal water and a standard diet from weaning to postnatal day （PND） 50. Perinatal exposure to BPA resulted in significantly increased body weight, visceral adipose tissue, abnormal serum lipids, and lower adiponectin （ADP） levels in both female and male offspring rats. Liver adipose triglyceride lipase （Atgl） mRNA levels and ADP protein in visceral adipose tissue were significantly decreased in BPA-exposed offspring rats. In both female or male offspring rats, obesity and dyslipidemia induced by perinatal exposure to BPA were associated with down regulation of Atgl mRNA in liver and ADP protein in visceral adipose tissue.

Microglia activation in the offspring of prenatal Poly I:C exposed rats:a PET imaging and immunohistochemistry study

Background The well-known ‘pyrotherapy’ of Julius Wagner-Jauregg might be the beginning of the study on the immunological concepts of schizophrenia. As the primary immune effector cells in the brain, microglia play a pivotal role in neuroinfammatory processes. Maternal viral infection during pregnancy is associated with an increased risk for psychiatric disorders with presumed neurodevelopmental origin, including autism spectrum disorders and schizophrenia. The present study was to quantify microglia activation in vivo in the mature offspring of rats exposed to polyriboinosinic–polyribocytidilicacid （Poly I：C） during pregnancy using ^11C-PK11195 positron emission tomography （PET） and immunohistochemistry.Objective The study aimed to quantify microglia activation in vivo in the prefrontal cortex and hippocampus in mature offspring of prenatal Poly I：C exposed rats.Methods Offspring of Poly I：C-treated dams were the model group, offspring of saline-treated dams were the control group. Behavioural test for two groups was taken by spontaneous activity, prepulse inhibition （PPI） and latent inhibition （LI） test （including active avoidance conditioning task and passive avoidance conditioning task）. Randomly selected successful model rats were assessed by behavioural test in the model group and control group rats. 11C-PK11195 micro-PET/CT and immunohistochemistry were performed on the selected rats to measure microglia activation.Results The treatment group showed hyperlocomotion and defcits in PPI and LI compared with the control group. The treatment group also showed an increased 11C-PK11195 uptake ratio in the prefrontal cortex （t=-3.990, p=0.003） and hippocampus （t=-4.462, p=0.001）. The number of activated microglia cells was signifcantly higher in the treatment group than in the control group （hippocampus： t=8.204, p〈0.001; prefrontal： t=6.995, p〈0.001）. Within the treatment group, there were signifcant correlations between the behavioural parameters and the activation of microglia as measured by PET and immunohistochemistry.Conclusions The present study demonstrated microglia activation in vivo in the prefrontal cortex and hippocampus in mature offspring of prenatal Poly I：C exposed rats. This study suggests that microglia activation may play a possible or potential role in the pathogenesis of schizophrenia.

Effects of dexmedetomidine on developmental damage of hippocampal neurons in offspring rats induced by sevoflurane inhalation anesthesia during pregnancy

Objective:To investigate the effects of developmental damage of hippocampal neurons in offspring rats induced by sevoflurane inhalation anesthesia during pregnancy and its related mechanisms.Methods:Eighteen pregnant female Sprague-Dawley(SD)rats were randomly divided into three experimental groups:the control group(intraperitoneal injection of 0.9%sodium chloride solution 100 mL),the sevoflurane inhalation anesthesia group(inhalation of 1 MAC sevoflurane for 6 h and intraperitoneal injection of 0.9%sodium chloride solution 100 mL),and the dexmedetomidine combined with sevoflurane inhalation anesthesia group(inhalation of 1 MAC sevoflurane for 6 h and intraperitoneal injection of dexmedetomidine 100 mL),with 6 rats in each group.On the day of birth,the offspring rats of each experimental group were randomly selected.And blood gas analysis was performed with left ventricular artery blood of each offspring.The expression of cleaved-caspase-3 in hippocampal neurons was measured by Western blot.The mRNA expressions of growth-associated protein-43(GAP-43)and neuronal nitric oxide synthase(nNOS)in hippocampus of offspring rats were detected by real-time RT-PCR.The protein expressions of GAP-43 and nNOS were tested by immunohistochemistry and Western blot.Results:Compared with the control group,cleaved-caspase-3 expression in hippocampal neurons of offspring rats in sevoflurane inhalation anesthesia group increased significantly.Cleaved-caspase-3 in hippocampal neurons of offspring after dexmedetomidine combined with sevoflurane inhalation anesthesia was dramatically lower than that in sevoflurane inhalation anesthesia group.Compared with the sevoflurane inhalation anesthesia group,dexmedetomidine combined with sevoflurane inhalation anesthesia could markedly up-regulate the mRNA and protein expressions of GAP-43 and nNOS.Conclusion:Dexmedetomidine can protect hippocampal neurons from developmental damage induced by sevoflurane inhalation anesthesia during pregnancy,which may be related to the up-regulation of the mRNA and protein expressions GAP-43 and nNOS.

Sexual differences of the effects of prenatal stress on the expression of extracellular signal-regulated kinaseas in the hippocampus of offspring rats

BACKGROUND： Prenatal stress has been shown to inhibit cell proliferation in the dentate gyrus and hippocampus, reduce hippocampal volume, and cause neuronal loss and oxidative damage in the hippocampus of offspring rats, but the sexual difference of the effects on offsprings is seldom referred to. OBJECTIVE： To observe the effect of prenatal stress to adult pregnant rats on expression of extracellular signal-regulated kinases （ERK） in hippocampus of the offspring rats of different genders. DESIGN ： A randomized and control animal experiment.SETTING： Department of Physiology and Pathophysiology, School of Medicine, Xi＇an Jiaotong University. MATERIALS ： The experiments were carried out in the Key Laboratory of Environment and Gene Related Diseases （Xi＇an Jiaotong University）, Ministry of Education between October 2005 and March 2006. Fifteen female and five male adult Sprague-Dawley rats were adopted. Female rats weighing 230-250 g and male rats weighing 280-350 g were used. METHODS： The virgin female rats were placed overnight with adult male rats （3：1） for mating. A total of twelve pregnant rats were randomly assigned to prenatal stress group （PNS group, n=6） and control group （n=6）. The pregnant rats of the PNS group were exposed to restraint stress on days 14-20 of pregnancy three times a day, 45 minutes for each time . The restraint device was a transparent plastic tube （6.8 cm in diameter） with air holes for breathing and closed end. The length could be adjusted to accommodate the size of the animals. To prevent habituation of animals to the daily procedure, restraint periods were randomly shifted within certain time periods （8：00-11：00, 11：00-14：00, and 16：00-19：00）. After birth, offsprings of all groups were culled to 8-10 litters in each group and housed in the same animal room, and kept together with their biologic mothers. The pregnant rats of the control group were left undisturbed. On day 21, after all the offspring were weaned, male and female pups were separated and housed four in each cage respectively until test at 30 days of age. At the end of postnatal day 30, one male and female offspring rats from the same dam were selected with a random choice and a total of 24 animals from 12 different dams were used. The experimental rats were sacrificed by decapitation under anesthesia. Bilateral hippocampal tissues were isolated and homogenized in cold condition. Alkaline carbonate buffer （BCA） method was used to detect the concentration of extracellular signal-regulated kinases （ERK）, then mixed with loading buffer, the constant voltage was 100 V. Finally, BCIP/NBT staining and electrDphoresis were performed, the absorbance （A） value for the bands was detected with the Bandscan analytical software, and the expression of ERK in hippocampus of offspring rats of different genders in each group was quantitatively analyzed. MAIN OUTCOME MEASURES： The level of ERK expression in hippocampus of offspring rats of different genders in each group was observed.RESULTS： All the 24 offspring rats were involved in the analysis of results. ① The staining results of ERP activity in the extract of brain tissue detected with Western blotting technique and specific antibody analysis showed that the ERP in hippocampus of offspring rats had two subtypes of ERK-1 and ERK-2, and the latter was the main type.② Standardized by the average A value in the control group, the quantitative data of the general A value of total ERK showed that the expression of ERK-2 in hippocampus of female offspring rats was obviously higher in the PNS group than in the control group （A value： 126±6.76,100±4.89,P〈 0.01）. ③The expression of ERK-2 had no obvious difference between the female and male offspring rats in the control group.④ The expression of ERK-2 in hippocampus of male offspring rats was a little higher in the PNS group than in the control group （A value： 104±6.27,102±5.48,P 〉 0.05）. CONCLUSION ： PNS significantly affects the increase of ERK expression in hippocampus of female offspring rats, but has no obvious influence on that of male ones.

Methyl Donors Supplementation Attenuates the Adverse Effects of Maternal High Fructose Diet of Offspring Emotional and Cognitive Behaviors

Free Fatty acid is an end-product of hepatic metabolism of fructose. Most of past studies have demonstrated significant relationship between gestational high fat diet and metabolic and physiology outcomes in offspring. However, there is a scarce of data extended to the effects of high fructose diet-fed dams on juveniles’ progeny. Therefore, the present experiment was designed to examine the later effects of maternal high fructose diet intake during pregnancy and lactation on juvenile offspring rats emotional behaviors and memory abilities. We tested whether methyl donors supplemented to that high fructose diet could reverse the adverse effects. We found at two months of age, anxiety-like behavior and depression-like behavior were elevated in off springs of mother fed to high fructose diet and a sex difference effect with males were more affected than females. In addition, behavioral outcomes indicated that the high fructose diet also impaired spatial working and recognition memories in the Y-maze and object recognition test respectively. Blood glucose intolerance increased significantly in juvenile males rats of dams fed with high fructose diet when compared to females. However, a supplementation of the maternal diet with methyl donors attenuated all these changes. Our study suggested a controlled fructose diet supplemented to methyl donors during critical period of brain developing (in utero and pre-weaning stage), otherwise that could induced irreversible detrimental effects on offspring behavior and cognitive health.

Folic acid supplementation attenuates hyperhomocysteinemia-induced preeclampsia-like symptoms in rats

Folic acid participates in the metabolism of homocysteine and lowers plasma homocysteine levels directly or indirectly. To establish a hyperhomocysteinemic pregnant rat model, 2 mL of DL-homocysteine was administered daily by intraperitoneal injection at a dose of 200 mg/kg from day 10 to day 19 of gestation. Folic acid was administered by intragastric administration at a dose of 20 mg/kg during the period of preeclampsia induction. Results showed that systolic blood pressure, proteinuria/creatinine ratio, and plasma homocysteine levels in the hyperhomocysteinemic pregnant rats increased significantly, and that body weight and brain weight of rat pups significantly decreased. Folic acid supplementation markedly reversed the above-mentioned abnormal changes of hyperhomocysteinemic pregnant rats and rat pups. These findings suggest that folic acid can alleviate the symptoms of hyperhomocysteinemia- induced preeclampsia in pregnant rats without influencing brain development of rat pups.

生命早期维生素D缺乏对仔鼠生长发育和亚临床骨健康的影响

目的探讨生命早期维生素D缺乏对仔鼠生长发育和亚临床骨健康的影响。方法选择健康成年SD大鼠27只,雄性9只、雌性18只。所有雌性SD大鼠按随机数字表法随机分为对照组、维生素D缺乏组(VDD组)、维生素D补充组(VDS组),每组6只。VDD组和VDS组予维生素D缺乏饲料喂养,对照组和所有雄性SD大鼠予标准饲料喂养。喂养4周,按雌雄比2∶1合笼交配。交配成功后,对照组与VDS组予标准饲料喂养和白炽灯照明,VDD组继续予维生素D缺乏饲料喂养和正白光LED灯照明,直至仔鼠21天离乳。所有仔鼠按母鼠饲养条件喂养至出生第7周末。仔鼠出生第1、2、3、4周末,称量体质量,测量身长和尾长。仔鼠出生第7周末,麻醉后经心脏取血,离心留取血清。采用偶氮砷Ⅲ法检测血清Ca^(2+),采用双位点酶免疫法检测血清甲状旁腺激素(PTH),采用ELISA法检测血清25-羟基维生素D[25-(OH)D];采用双能X射线骨密度仪检测全身骨矿物质含量和骨密度;采用酶法检测血清磷,采用ELISA法检测血清胰岛素样生长因子1(IGF-1),采用化学发光免疫分析法检测血清Ⅰ型前胶原N端延长肽(P1NP)、碱性磷酸酶(ALP)。结果对照组和VDS组仔鼠出生第1~4周末体质量、身长、尾长均高于VDD组仔鼠同期(P均<0.05),并且VDS组仔鼠出生第1~4周末体质量、身长、尾长均高于对照组仔鼠同期(P均<0.05)。出生第7周末,对照组和VDS组仔鼠血清Ca^(2+)、25-(OH)D、ALP、磷、IGF-1水平及骨矿物质含量和骨密度均高于VDD组仔鼠,血清PTH、P1NP水平均低于VDD组仔鼠(P均<0.05);VDS组仔鼠血清ALP、磷、IGF-1水平及骨矿物质含量和骨密度均高于对照组仔鼠,血清P1NP水平低于对照组仔鼠(P均<0.05)。结论生命早期维生素D缺乏可影响仔鼠生长发育并引起亚临床骨健康,而及时补充维生素D则能促进仔鼠生长发育,逆转亚临床骨健康。

砷对大鼠子代免疫功能影响的研究

为了解砷对大鼠子代免疫功能的影响，本研究采用了两代一窝繁殖试验的方法，观察了暴露于Ａｓ２Ｏ３大鼠子代免疫功能的变化。结果显示：在７５ｍｇ／Ｌ的高剂量Ａｓ２Ｏ３暴露组脾和胸腺的脏器系数明显低于对照组，血红蛋白和Ｔ淋巴细胞数显著降低，炭粒廓清速率的廓清指数和吞噬指数也明显低于对照组；而在低剂量和中剂量Ａｓ２Ｏ３暴露组其免疫学指标的改变则不明显。说明砷可以通过胎盘屏障。

甲醛染毒对大鼠子代脏器及血液细胞的影响

[目的]探讨甲醛对大鼠子代脏器及血液细胞的影响。[方法]按一代一窝繁殖法进行生殖毒性试验，选用体重110-130g Wistar大鼠120只。随机分为4组，每组雌鼠20只、雄鼠10只，采用静式吸入染毒。雌、雄大鼠每天染毒1h，每周7d，连续染毒24周，高、中、低组的甲醛浓度分别为（119．6±15．4）、（25．2±4．6）、（4．8±1．3）mg／m^3，对照组为室内空气；并检测仔鼠脏器系数及血常规。[结果]随着染毒浓度的增加、时间的延长，各染毒组子代大鼠体重与对照组比较呈下降趋势（P〈0．05）；雄性仔鼠心、肺、脑、睾丸和雌性仔鼠肺、脑的脏器系数呈上升趋势，而肝脏的脏器系数呈下降趋势（P〈0．05）；仔鼠血液中白细胞、中性粒细胞、单核细胞及血小板值呈现下降趋势，而嗜酸性粒细胞值呈上升趋势（P〈0．05）。[结论]说明甲醛可抑制大鼠子代的生长发育，损伤肝脏、脑、肺、心及睾丸等器官，并可影响仔鼠的非特异性免疫及凝血功能。

母体暴露壬基酚对仔鼠肝脏的损伤作用

[目的]研究母体暴露壬基酚对仔鼠肝脏的损伤。[方法]母鼠孕14￣19 d灌胃壬基酚(0、40、80、200mg/kg),检测F1仔鼠90 d龄肝脏GSH-PX、SOD活性及MDA含量。[结果]NP 80、200 mg/kg组肝脏GSH-PX及SOD活性明显下降;NP 200 mg/kg组MDA含量上升,病理切片见肝脏中央静脉扩张充血,肝细胞脂肪变性或灶状坏死。[结论]壬基酚可透过胎盘屏障致仔鼠肝脏脂质过氧化损伤。

高锰对雌性仔鼠大脑发育的影响

用不同锰含量的饮水（分别为２和１０ｇ／Ｌ）使孕鼠染锰，研究对子代大脑发育的影响。结果表明：（１）高剂量染锰组仔鼠大脑额叶和顶叶皮质厚度比低剂量组和对照组显著变薄，而胶质细胞纤维酸蛋白（ｇｌｉａｌｆｉｂｒｉｌａｒｙａｃｉｄｐｒｏｔｅｉｎ，ＧＦＡＰ）免疫反应强度及其阳性反应产物平均相对密度均明显增高；（２）高、低剂量染锰组仔鼠的扣带回皮质厚度显著较对照组增厚，ＧＦ－ＡＰ反应强度及其阳性反应产物相对密度显著升高；（３）高剂量染锰组仔鼠胼胝体的面积较对照组和低剂量组显著增大，ＧＦＡＰ免疫反应及其阳性反应产物相对密度明显增高，而低剂量组与对照组之间无差异。

孕期壬基酚暴露对雄性仔鼠免疫功能影响

目的探讨孕期壬基酚暴露（NP）对雄性仔鼠免疫功能的影响。方法母鼠孕14~19 d灌胃NP（0,20,40,80,200 mg/kg）,仔一代（F1）雄性仔鼠于60 d龄剖杀取脾脏、胸腺、血清,测免疫功能相关各项指标。结果NP80、200 mg/kg组脾脏、胸腺重量及脏器系数显著低于阴性对照组（P〈0.05）,且脾脏重量、脏器系数与染毒剂量呈负相关（r=-0.884）;NP200 mg/kg组仔鼠血清γ-干扰素（IFN-γ）、白细胞介素6（IL-6）的水平与阴性对照组比较显著降低（P〈0.05）,且血清IFN-γ与染毒剂量呈负相关（r=-0.980）;NP200 mg/kg组脾淋巴细胞的增殖能力较阴性对照组低（P〈0.05）,脾、胸腺内淋巴细胞显著减少,出现灶状坏死。结论壬基酚可通过胎盘屏障,200 mg/kg对雄性仔鼠免疫功能有抑制作用。

甲醛染毒对大鼠子代神经行为发育的影响

[目的]探讨甲醛对大鼠子代早期神经行为发育的影响。[方法]进行两代一窝繁殖试验,选用体重110-130 g Wistar大鼠120只,随机分为4组,染毒浓度分别为,高浓度组:(119.6±15.4)mg/m3、中浓度组:(25.2±4.6)mg/m3、低浓度组:(4.8±1.3)mg/m3、对照组:室内空气。采用静式吸入法,每天染毒1 h,雄鼠连续染毒至交配后,雌鼠连续染毒至子代断乳,用一组行为毒理学方法检测雌、雄大鼠暴露于甲醛后子代生理及神经行为发育的情况。[结果]随着染毒浓度的增加,F1、F2代大鼠张耳、门齿萌出和开眼3项反映早期生理发育指标和平面翻正反射和悬崖回避试验阳性率呈逐渐降低趋势(P<0.05),学习、记忆达标训练次数和达标时间明显增多和延长(P<0.05),高浓度组学习达标时间、记忆达标时间分别高达(307.0±49.5)s、(279.7±42.35)s,持续游泳时间及耐缺氧时间均逐渐缩短,分别为(31.63±7.50)min、(43.40±4.94)min,P<0.05。[结论]甲醛对子代大鼠的神经系统有明显的损害作用。

纳米颗粒物对大鼠妊娠结局及其子代近期记忆的影响

目的目的探讨不同化学成分的纳米颗粒物对大鼠妊娠结局及其子代发育的影响。方法将受孕大鼠随机分为4组(纳米碳、纳米氧化锌、纳米碳锌复合颗粒及牛血清对照组),采用气管滴注染毒方式,剂量为7.5mg/kg bw,每天一次,连续5天。待孕鼠自然分娩,记录妊娠率、生产仔鼠数、仔鼠4天存活率及仔鼠行为神经等发育状况。结果纳米氧化锌、碳锌复合颗粒染毒组孕鼠妊娠率分别为57.2%和66.7%,均低于对照组及纳米碳组的100.0%;各组所生产仔鼠均数无显著差异;在哺乳期纳米氧化锌组仔鼠第4、7和21天体重均显著高于其他实验组。水迷宫结果显示,纳米碳锌复合颗粒组在第二、第三潜伏期潜伏时间较其他各组明显增加,纳米碳、纳米氧化锌组的潜伏时间与对照组相比差异无显著性。平面翻正反射、空中翻正反射实验结果与对照组相比差别无显著性。结论该实验条件下,纳米氧化锌对大鼠的生殖有一定的毒性作用,对仔鼠的生长发育有一定的促进作用;纳米碳锌复合颗粒对子代近期记忆有负面影响。

妊娠中末期邻苯二甲酸(2-乙基己基)酯暴露对母鼠妊娠结局及子鼠生长发育的影响

目的观察妊娠中末期邻苯二甲酸(2-乙基己基)酯(DEHP)经口染毒对母鼠妊娠结局及子鼠生长发育的影响。方法 50只Wistar雌鼠妊娠12 d时随机分入4个染毒组(DEHP浓度分别为1、250、750、1 000 mg/kg,n=10)和1个对照组(n=10);染毒组DEHP灌胃染毒至妊娠17 d,对照组仅给予玉米油。观察DEHP对母鼠行为、体质量、妊娠结局、脏器系数的影响,以及DEHP对子鼠体质量和雌性子鼠阴道开口的影响。结果染毒期间,各DEHP染毒组母鼠体质量增加,各染毒组每窝活胎数量与对照组比较,差异均无统计学意义(P>0.05);未观察到死胎、畸胎。子鼠出生第22天,各染毒组母鼠子宫、卵巢、肝脏、脾脏、肾脏、胸腺、下丘脑、脑、肾上腺的脏器系数与对照组比较,差异均无统计学意义(P>0.05)。各染毒组子鼠出生后1～22 d体质量增加值与对照组比较,差异均无统计学意义(P>0.05)。出生后66 d,750 mg/kg及1 000 mg/kg DEHP染毒组雌性子鼠出现阴道闭锁畸形,分别占62.50%和81.25%,其余各组雌性子鼠阴道全部正常开口。结论 750、1 000 mg/kg DEHP妊娠中末期经口染毒未导致大鼠母体、胚胎一般毒性,可观察到雌性子代成年后阴道闭锁现象。

宫内慢性缺氧对子代大鼠血压的影响

目的探讨宫内慢性缺氧对子代大鼠血压的影响。方法 SD大鼠孕鼠于妊娠第7~21天,每日置于氧气浓度为10%±1%的低压氧舱3 h,待分娩后观测其子代大鼠体重、主要脏器重量及血压的变化。结果宫内缺氧组仔鼠出生后第1天体重显著低于对照组（P〈0.01）,但出生后第20天体重与对照组无显著性差异;宫内缺氧组仔鼠肝脏于出生后第1、20天以及雄性仔鼠肾脏于出生后3月、7月的重量显著低于对照组（P〈0.05）;5月龄、7月龄宫内缺氧组子代雄性大鼠血压均比同性别对照组显著升高（P〈0.05）,且呈现随年龄增长而逐渐加重趋势,但宫内缺氧子代雌性大鼠血压与对照组相比无显著性差异。结论慢性宫内缺氧可能是引起大鼠肝、肾、血管组织程序控制的应激因素之一。它可诱发子代雄性大鼠血压升高,呈现性别依赖现象,并随年龄增长有逐渐加重倾向。

氟对不同世代大鼠大脑皮质细胞凋亡的影响

为研究氟中毒能否引起世代蓄积而对不同世代动物大脑造成损伤,试验采用离乳Wistar大鼠16只,随机分为2组,对照组饲喂大鼠标准饲料,饮自来水;高氟组饲喂大鼠正常饲料,饮含氟化钠(NaF)100 mg/L的去离子水。饲喂3个月,生产子二代和子三代大鼠,仔鼠饲喂采用与其母鼠相同的处理。取0、10、20、30、60、90日龄的不同世代大鼠,分别宰杀,取大脑,制成单细胞悬液,采用流式细胞仪检查其细胞凋亡情况。结果显示,与对照组相比,不同日龄高氟组二代、三代大鼠大脑皮质细胞凋亡率升高。与二代大鼠相比,不同日龄氟中毒三代大鼠大脑皮质细胞凋亡程度增高,10、20、60、90日龄时差异显著(P<0.05)。提示,氟中毒可以引起世代蓄积,接触氟环境时间越长,其动物子代大脑损伤越严重。