软食喂养对发育中大鼠咬肌乙酰胆碱受体亚基mRNA表达的影响  

The effects of soft-diet feeding on the mRNA expression of nicotinic acetylcholine receptor in rat masseter muscle during postnatal development.

作　　者：马军利[1] 刘洪臣[1] 王冠超[1] 鄂玲玲[1] 王东胜[1] 

机构地区：[1]解放军总医院口腔医学中心,北京100853

出　　处：《临床口腔医学杂志》2008年第8期473-475,共3页Journal of Clinical Stomatology

基　　金：国家级自然科学基金资助(30572066)

摘　　要：目的:检测不同硬度食物喂养下,大鼠在咀嚼形成的不同阶段,咬肌乙酰胆碱受体亚基mRNA(nicotinic acetylcholine receptor,nAchR)的表达变化。方法:40只出生后18d的大鼠,随机分为硬食组、软食组,分别喂养营养成分相同的固体、粉状鼠粮,于大鼠3w、4w、6w、9w龄时取表层咬肌,半定量RT-PCR方法检测nAchRγ/ε/δ亚基mRNA的表达变化情况。结果:3周时两组大鼠咬肌γ-nAchR mRNA表达均较低,软食组强于硬食组(p<0.05),4周时,硬食组没有γ-nAchR mRNA表达,软食组仍有微弱表达,6～9周两组均无γ-nAchR mRNA表达。两组大鼠ε-nAchR mRNA表达变化没有显著差异,4～9周表达均明显低于3周(p<0.05)。3～9周龄两组大鼠咬肌δ-nAchR mRNA表达均呈下降趋势,软食组下降程度更为明显,9周时明显低于硬食组(p<0.05)。结论:大鼠咬肌γ/ε-nAchR亚基转化在出生后3～4周完成,软食喂养可以延缓γ-nAchR的消亡与γ/ε-nAchR亚基转化,但不能阻止这一过程;软食喂养对不同nAchR亚基mRNA表达的影响具有选择性。Objective： To observe the expression of nicotinic acetylcholine receptor （nAchR） mRNA in masseter muscle of rat under different food consistency during postnatal development. Method： Forty rats （18days after birth） were randomly divide into solid group and soft group,and were fed with solid diet and powder diet respectively,the superficial masseter muscle were dissected at postnatal 3,4, 6,9 weeks, semi-quantitive RT-PCR was performed to determine the expression of γ / ε / 8 subunit of nAchR. Result： At postnatal 3 weeks, the expression of γ-nAchR mRNA in soft group was stronger than solid group （p 〈 0.05）,though both of which were low; at 4 postnatal weeks,γ-nAchR mRNA showed week expression in soft group, contrary to that, no expression was detected in solid group. From postnatal 6 to 9 weeks, there was no expression of γ-nAchR mRNA in both groups; soft diet feeding had no influence on expression of ε-nAchR mRNA, which was significantly lower after postnatal 3 weeks in both groups （p 〈 0.05） ; from postnatal 3 to 9 weeks, expression of δ- nAchR mRNA declined in both groups, soft group showed more notable reduction,which was significantly lower than solid group at postnatal 9 weeks. Conclusion： The subunit shift from γ to e in rat master muscle complete between postnatal 3 to 4 weeks,which could be delayed, not prevented,by soft diet feeding;soft diet feeding could selectively influence the expression of certain type of nAchR subunit at mRNA level.

关 键 词：软食 咀嚼 发育 咬肌 乙酰胆碱受体 

分 类 号：Q786[生物学—分子生物学]