α7nACh受体在孕期烟熏抑制新生大鼠RRDA中的作用

发布时间：2018-03-28 11:38

本文选题：妊娠期烟熏　切入点：新生大鼠　出处：《新乡医学院》2014年硕士论文

【摘要】：背景众所周知吸烟成瘾已成为这个社会不可忽视的问题,抽烟不仅对吸烟者本人乃至周围的人甚至子代都产生不良影响。孕期尼古丁暴露会导致胎儿造成极大的危害,如：致畸、宫内缺氧、低体重儿、先天性疾病、婴儿猝死症候群等。烟碱是香烟中的主要生物碱,在妊娠期烟碱暴露所致胎儿中枢性呼吸异常中起关键作用,而稳定的节律性呼吸对于维持机体正常的生命活动至关重要。因此,研究孕期尼古丁暴露对新生大鼠延髓脑片基本节律性放电和在体耗氧量的作用至关重要,为进一步明确孕期尼古丁暴露对子代延髓呼吸中枢的抑制作用,并为相关疾病的预防和治疗提供新思路和实验基础。目的研究妊娠期烟熏对子代延髓呼吸中枢基本节律性呼吸放电及延髓呼吸中枢a7nACh受体(a7nicotinic acetylcholinergic receptor, a7nAChR)蛋白和基因表达的变化,探讨α7nAChR在孕期烟熏中所致子代呼吸抑制中的作用和机制。方法0-3天Sprague-Dawley大鼠,雌雄不拘,随机分为对照组和实验组。对照组新生大鼠产自自然日夜规律、常规饲养的成年大鼠；实验组新生大鼠产自除常规饲养外,自合笼至分娩每日2次(8Am和8Pm)、置于80cm*60cm*100cm*烟熏箱中8只香烟烟熏30min的大鼠。 1.用新生大鼠离体延髓脑片标本记录反映延髓呼吸中枢功能的脑片基本节律性呼吸放电(rhythmic respiratory discharge activity, RRDA)。观察α7nAChR激动剂乙酰胆碱(acetylcholine,ACh)和拮抗剂银环蛇毒素(Alpha-bungarotoxin,α-BGT)对对照组和实验组RRDA的作用,分析α7nAChR是否对RRDA有抑制作用,以明确α7nAChR是否参与孕期烟熏对子代的呼吸抑制作用。 2.采用Western Blot技术检测α7nAChR在延髓呼吸中枢面神经后核内侧区神经元上的表达,明确孕期烟熏是否减少α7nAChR在延髓呼吸中枢面神经后核内侧区神经元上的表达。 3.采用qRT-PCR技术检测α7nAChR mRNA在延髓呼吸中枢面神经后核内侧区神经元上的表达,明确孕期烟熏是否减少α7nAChR mRNA在延髓呼吸中枢面神经后核内侧区神经元上的表达。分析α7nAChR功能改变与受体和αRNA表达是否一致,是否存在相关性。结果 1.对照组和实验组脑片放电60min内稳定无衰减,实验模型稳定可靠。实验组脑片放电弱于对照组(以对照组为100%,实验组20min时TI88.23±3.17%、IA89.52±4.74%、RC90.06±4.57%)；α7nAChR激动剂ACh对实验组和对照组脑片放电都有兴奋作用,对照组兴奋效果强于实验组(实验组变化率分别13.05±0.46%、10.37±0.49%、7.65±±±0.40%；对照组为：19.67±0.54%、17.55±0.49%18.04±0.58%)；α7nAChR拮抗剂a-BGT对实验组和对照组脑片放电都有抑制作用,对照组抑制效果强于实验组(实验组变化率分别为9.67±0.50%、8.43±±±0.49%、6.67±0.53%;对照组为：16.65±0.45%、14.92±0.49%、14.33±0.43%)。 2. Western Blot实验结果显示,与对照组相比,实验组α7nAChR在延髓呼吸中枢面神经后核内侧区神经元表达减少(对照组1.012±0.090、实验组0.604±0.034)。 3qRT-PCR实验结果显示,与对照组相比,实验组α7nAChRmRNA在延髓呼吸中枢面神经后核内侧区神经元表达水平下调(对照组1.004±0.101、实验组0.809±0.069)。结论 1.孕期烟熏抑制新生鼠延髓脑片基本节律性呼吸放电、抑制α7nAChR对RRDA的调节作用,下调α7nACh受体蛋白和mRNA表达水平。 2.抑制α7nACh受体活性及功能,通过下调α7nACh受体蛋白水平和受体mRNA表达水平使延髓呼吸中枢面神经后核内侧区神经元数量减少、功能下降可能是孕期烟熏抑制子代延髓中枢呼吸功能的机制之一。
[Abstract]:Background : It is well known that smoking addiction has become a non - negligible problem in society . Smoking is not only harmful to smokers themselves or even those around them . The exposure to nicotine in pregnancy plays a key role in fetal central respiratory abnormalities due to exposure to nicotine .

Objective To study the effect and mechanism of 伪 - 7nCR on the respiratory depression in children during pregnancy .

Methods Sprague - Dawley rats were randomly divided into two groups : control group and experimental group .
In the experimental group , the newborn rats were fed twice daily ( 8Am and 8Pm ) except for routine feeding , and were placed in 80 cm * 60 cm * 100 cm * smoking oven for 30 min .

1 . The basic rhythmic respiratory discharge activity ( RRDA ) of the brain slices reflecting the function of the medullary respiratory center was recorded from the specimen of the isolated medulla of the neonatal rat . The effect of 伪 - bungarotoxin ( 伪 - BGT ) on RRDA in the control group and experimental group was investigated .

2 . Western Blot was used to detect the expression of 伪7nCR on the neurons in the medial region of the nucleus of the central facial nerve of the medullary respiratory center .

3 . Using qRT - PCR technique to detect the expression of 伪7nCR mRNA in the medial region of the nucleus of the central facial nerve of the medullary respiratory center .

Results

1 . The experimental model was stable and reliable in the control group and the experimental group , and the experimental model was stable and reliable . The experimental group was weaker than the control group ( 100 % in the control group , TI88.23 卤 3.17 % , IA89.52 卤 4.74 % , RC90.06 卤 4.57 % ) .
In the experimental group and the control group , there was an exciting effect on both the experimental group and the control group . The control group was more excited than the experimental group ( 13.05 卤 0.46 % , 10.37 卤 0.49 % , 7.65 卤卤 0.40 % , respectively ) .
The control group was 19.67 卤 0.54 % , 17.55 卤 0.49 % 18.04 卤 0.58 % ;
The results showed that a - BGT inhibited the discharges of brain slices in the experimental group and the control group , and the control group was stronger than the experimental group ( 9.67 卤 0.50 % , 8.43 卤卤 0.49 % , 6.67 卤 0.53 % , 14.92 卤 0.49 % , 14.33 卤 0.43 % ) .

2 . Compared with the control group , the expression of 伪 - 7nR _ ( R ) R _ ( R ) R _ ( R _ ( R ) R _ ( R ) _ ( R _ ( R ) R _ ( R ) _ ( R _ ( R ) R _ ( R ) _ ( R _ ( R ) _ ( R ) _ ( R _ ( R ) _ ( R ) _ ( R _ ( R ) _ ( R ) _ ( R _ ( R ) _ ( R ) _ ( R _ ( R ) _ ( R ) _ ( R _ ( R ) _ ( R ) _ ( R _ ( R ) _ ( R ) _ ( R _ ( R ) _ ( R ) _ ( R ) in the

The results of 3qRT - PCR showed that the expression of 伪 - 7nCDRmRNA in experimental group was lower than that of control group ( 1.004 卤 0.101 in the control group and 0.809 卤 0.069 in the experimental group ) .

Conclusion

1 . During the pregnancy period , the basic rhythmic respiratory discharge was inhibited by smoke suppression in neonatal rats , and the regulatory action of 伪7nCR on RRDA was inhibited , and the expression level of 伪7nAl _ 1 receptor protein and mRNA was downregulated .

2 . The inhibition of the activity and function of 伪 - 7nach receptor , the decrease of the number of neurons in the medial region of the nucleus of the nucleus of the medullary respiratory center after downregulation of the level of the 伪 - 7nabolol receptor protein and the level of receptor mRNA , the decrease in function may be one of the mechanisms for the inhibition of the respiratory function of the nucleus of the medulla of the subnucleus during pregnancy .

【学位授予单位】：新乡医学院
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R714.2

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