BDE-209暴露联合窒息对子鼠神经发育的影响

发布时间：2018-01-24 03:29

本文关键词： BDE-209 窒息神经行为学表现 capase-3 mTOR　出处：《广州医科大学》2014年硕士论文　论文类型：学位论文

【摘要】：研究背景: 因其具有良好的阻燃性能和尚未明确的毒理学机制，，十溴联苯醚(Decabrominated diphenyl ether，BDE-209)被广泛应用于电路板、纺织品、塑料制品和建筑相关材料中[1]。研究表明，BDE-209在使用和生产过程中可经渗出、挥发等方式释放到周围环境中，并通过食物链最终在人体内蓄积。中国是世界上使用及生产BDE-209最多的国家。目前越来越多的研究显示BDE-209是近年我国环境中含量增长较快的持久性环境有机污染物，平均每天人体经呼吸摄入416ngBDE-209[2]，人体血清、乳汁及脐血中BDE-209平均浓度分别为9.472ng/gliquid weight，1.867ng/g liquid weight和78.103ng/g liquid weigh[3]。因为体内蓄积的差异性、解毒代谢和排除机制的不完善，处于生长发育时期的婴幼儿体内BDE-209的暴露水平远高于成年水平[4]。此外，胚胎及婴幼儿时期是脑神经发育和功能完善的关键时期，对外源性毒物的损伤尤为敏感。因此，BDE-209对神经系统发育的影响备受关注。围产期窒息是导致神经发育异常的主要原因之一。据统计，70-80%的神经发育异常是由围产期窒息所致。随着医疗水平的提高，围产期窒息发生率已明显减低，但因导致神经系统发育异常原因众多，后者的发生率并未降低，约为为1/1000。环境化学因素是众多造成神经发育异常的因素中备受关注的一种。此外，日益增多的证据表明，围产期窒息可增加已受环境因素影响的胎儿发生神经发育异常的风险[18]。目前，我国有关神经发育异常环境因素的研究较少，其对妊娠结局影响的研究亦不多。因此，在我国的环境污染控制工作匮乏,当今环境污染日益增加的形势下，探讨环境因素与围产期窒息对神经系统发育异常影响的联合作用有着重要的社会和经济意义。研究目的: 建立BDE-209围产期单独暴露或联合产时窒息的SD大鼠的子鼠模型。根据子鼠的生长发育及神经反射指标，海马组织中凋亡相关基因如caspase-3,mTOR的表达，在MORRIS水迷宫中的学习及记忆能力，初步探讨BDE-209或联合产时窒息对子鼠生长和神经发育可能造成的影响，为BDE-209的毒理学研究及窒息的神经损害作用提供理论依据。研究方法: 1.BDE-203围产期暴露自孕鼠受孕第一天开始，根据分组每日分别胃灌0mg/Kg（对照组）,0.6mg/Kg,6.0mg/KgBDE209。 2.产时窒息模型孕鼠于妊娠22天接受剖宫产手术，含有子鼠的双侧子宫被完整取出，根据分组立即娩出（非窒息组）或置于37℃水浴箱15分钟后娩出（窒息组），子鼠由代育母鼠哺育。 3.BDE209暴露联合窒息对子鼠生理发育的影响自出生后第一天至出生后第33天，每日检查子鼠张耳、全身绒毛、下牙萌出、开眼、上牙萌出、全身绒毛等生理发育指标。 4. BDE209暴露联合窒息对子鼠行为学的影响自出生后第一天至出生后第33天，每日检查子鼠痛觉反射、平面翻正、负趋地性、悬崖回避、听觉惊厥、空中翻正等神经反射指标和前肢悬挂试验等耐力试验。 5. BDE209暴露联合窒息对子鼠学习记忆的影响通过MORRIS水迷宫测试出生后第二十八天的雄性子鼠的学习记忆能力。 6. BDE209暴露联合窒息对子鼠海马组织中caspase3及mTOR基因表达的影响通过RT-PCR检测产出生后第6日雄性子鼠双侧海马组织中caspase-3基因及mTOR基因的表达。 7.统计学分析应用SPSS18.0软件进行统计学分析，数据结果以±s表示，行方差齐性检验和卡方检验，检验水准为α＝0.05。P0.05为差异有统计学意义。结果: 1.各组子鼠的痛觉反射、听觉惊厥、空中翻正等神经反射指标达标日龄的差异，无统计学意义（P0.05）。窒息组较非窒息组的子鼠，在平面翻正、负趋地性、悬崖回避达标日龄的差异有统计学意义（P0.05），窒息组或非窒息组内，不同剂量BDE-209暴露的子鼠间的各神经反射指标无统计学意义（P0.05）。 2.与对照组相比，0.6mg/KgBDE-209暴露联合产时窒息组雄性子鼠的上肢悬挂时间的差异有统计学意义（P0.05）。 3.各组子鼠的张耳、全身绒毛、下牙萌出、开眼、上牙萌出、全身绒毛、阴道开口、睾丸下降等生理发育指标的差异没有统计学意义（P0.05）。 4.各组雄性子鼠在MORRIS水迷宫中的定位航行试验所用的时间，空间探索试验中原平台象限滞留时间占总时间的百分比的差异无统计学意义（P0.05） 5.各组子鼠双侧海马中的caspase-3和mTOR基因表达，RT-PCR结果显示，各组mTOR基因表达水平的差异无统计学意义（P0.05）；与对照组相比，各组caspase-3的差异有统计学意义（P0.05），且与BDE-209暴露存在剂量关系。结论: 围产期BDE-209单独暴露和或联合窒息对子鼠可能存在一定的影响。
[Abstract]:Research background:
Because of its flame retardant properties and toxicological mechanism of good is not clear, ten polybrominated diphenyl ether (Decabrominated diphenyl, ether, BDE-209) is widely used in circuit boards, textiles, plastic products and related research of [1]. building materials show that BDE-209 production process by exudation in use and volatilization etc., released to the surrounding environment and through the food chain, eventually accumulate in the body. Chinese is used in the world and production of BDE-209 in most countries. Now more and more studies show that BDE-209 is the content of China's environment of persistent organic pollutants in the environment of rapid growth, the average daily intake of the body through the respiratory 416ngBDE-209[2], human serum, milk and umbilical blood in average BDE-209 the concentration were 9.472ng/gliquid weight, 1.867ng/g liquid weight and 78.103ng/g liquid weigh[3]. because of differences in the accumulation, metabolism and detoxification row The mechanism is not perfect, in the exposure period of growth and development of BDE-209 in infants is much higher than the level of [4]. in the embryonic and adult, the infant period is a critical period of brain neural development and function perfect, particularly sensitive to exogenous toxic injury. Therefore, BDE-209 has attracted much attention on the development of the nervous system.
Perinatal asphyxia is one of the main causes of abnormal neural development. According to statistics, 70-80% nerve dysplasia is caused by perinatal asphyxia. With the improvement of medical standards, perinatal asphyxia rate has decreased significantly, but due to nervous system abnormalities of many reasons, the latter did not reduce the incidence, about factors 1/1000. environmental chemistry is a concern due to many factors of abnormal neural development. In addition, the increasing evidence that perinatal asphyxia can increase the impact of environmental factors of fetal nerve dysplasia risk [18]. at present, our country related environmental factors of abnormal neural development is less, to study its effect on pregnancy the outcome is not much. Therefore, in China's environmental pollution control work is scarce, the environmental pollution is increasing under the situation of the environmental factors and perinatal asphyxia on The combination of the effects of the dysplasia of the nervous system has important social and economic significance.
The purpose of the study is:
Rat model of SD rats to establish BDE-209 perinatal asphyxia exposed alone or combined with intrapartum. According to the growth and development of offspring and nerve reflex index, hippocampus apoptosis related genes such as Caspase-3, the expression of mTOR, the ability of learning and memory in the MORRIS water maze, a preliminary study of BDE-209 or combined with birth asphyxia may influence the growth of rat offspring and neural development, and provide a theoretical basis for nerve damage toxicology and asphyxia BDE-209 role.
Research methods:
Perinatal exposure of 1.BDE-203
From the first day of pregnancy of pregnant rats, 0mg/Kg (control group), 0.6mg/Kg, 6.0mg/KgBDE209., respectively according to the group daily gastric perfusion (control group)
2. time asphyxiation model
On the 22 day of pregnancy of pregnant rats received cesarean section, containing the rat bilateral uterine was removed according to the packet delivered immediately (non asphyxia group) or under 37 DEG C water bath 15 minutes after childbirth (asphyxia group), rats by feeding. The surrogate mother
The effect of 3.BDE209 exposure and asphyxia on the physiological development of the rats
Since the first day of birth after thirty-third days, daily check at Zhang Er, body hair, teeth out of his eyes, teeth adorable, adorable, hair and other indicators of physiological development. The body
The effect of 4. BDE209 exposure combined with asphyxia on the behavior of children
Since the first day of birth after thirty-third days, the daily inspection of offspring pain reflex, surface righting reflex, negative geotaxis, cliff avoidance, auditory convulsion, air righting reflex and forelimb hanging test index and endurance test.
The effect of 5. BDE209 exposure combined with asphyxia on the learning and memory of the offspring
The ability of learning and memory of twenty-eighth days of male mice by MORRIS water maze test after birth.
Effects of 6. BDE209 exposure and asphyxia on the expression of Caspase3 and mTOR gene in the hippocampus of rat
The expression of Caspase-3 RT-PCR detected sixth days after the birth of bilateral hippocampus in male mice and mTOR gene.
7. statistical analysis
SPSS18.0 software was used for statistical analysis. The results of data were expressed in terms of + s, and the test of variance homogeneity and chi square test showed that the level of detection was 0.05.P0.05 = 1, the difference was statistically significant.
Result:
The 1. groups were pain reflex, auditory convulsion, air righting reflex and other indicators of the age difference, no statistical significance (P0.05). Group than in the non asphyxia group were asphyxia, is over the plane, negative geotaxis, cliff avoidance standard age difference was statistically significant (P0.05), asphyxia group or non asphyxia group, no statistical significance of each index reflex of different doses of BDE-209 exposed offspring between (P0.05).
2. compared with the control group, there was a significant difference in the upper limb suspension time between the 0.6mg/KgBDE-209 exposure group and the male asphyxia group (P0.05).
Ear, 3. groups offspring body hair, teeth and adorable, his eyes, teeth adorable, body hair, vaginal opening, testis physiological index of growth difference was not statistically significant (P0.05).
4., there was no significant difference in the time of location and voyage test of male rats in the MORRIS water maze, and the percentage of detention time in the central quadrant of the platform in the total time was not statistically significant (P0.05).
The expression of Caspase-3 and mTOR genes in 5. groups were bilateral hippocampus, RT-PCR results showed that the expression of mTOR mRNA level of the difference was not statistically significant (P0.05); compared with the control group, there was statistically significant difference between the groups of Caspase-3 (P0.05), and the exposure dose relationship with BDE-209.
Conclusion:
The perinatal BDE-209 exposure and or combined asphyxia may have a certain effect on the offspring.

【学位授予单位】：广州医科大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R714.7

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