茶多酚对蟾蜍坐骨神经干兴奋传导及骨骼肌收缩的影响.pdf

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1、茶多酚对蟾蜍坐骨神经干兴奋传导及骨骼肌收缩的影响马雪泷．-，吴孝兵，吴边(1．安徽师范大学生命科学学院。安徽芜湖241000；2．黄山学院生命与环境科学学院，安徽黄山245041)摘要：采用不同浓度的茶多酚溶液作用于蟾蜍坐骨神经一腓肠肌标本，发现lOlL茶多酚就可极显著地增强腓肠肌的收缩张力，且随着其浓度的加大而张力增加，直至茶多酚浓度超过160pg／L，肌肉张力开始回落，间接证明了茶多酚能够促进肌细胞内质网钙库中ca2+向细胞质的释放。实验还发现，茶多酚能够显著地缩短蟾蜍坐骨神经一腓肠肌标本单收缩的潜伏期，但不影响动作电位单独在

2、神经和肌肉细胞上的传导速度。这是由于茶多酚能提高蟾蜍神经一肌肉接头处微终板电位(加羽P)的频率和振幅，从而提高终板膜的兴奋性，使动作电位在神经一肌肉接头处的传递速度加快，缩短了突触延搁的时间。由此推测，这种兴奋性的加强还是源于茶多酚可促进神经纤维轴突末梢c内流，使细胞质中ca2浓度增加，导致乙酰胆碱释放量增加所致。关键词：茶多酚；蟾蜍；坐骨神经一腓肠肌；收缩张力；微终板电位中图分类号：B965文献标志码：A文章编号：1005—8141(2009)07—0577—04EfectofTeaPolyllmaol吼bIdlj雌Co~Oll

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5、nsionofthemuscletofal1．Thisfactprovedthatteapolyphenolcouldpromotethereleaseofc~2fromendofa~creficulumcalciumstoresinmusclecellsintothecytoplasmaccordingtothemusclecontractionmecha·nism．Itwasalsofoundthatteapolyphenolcouldsignificantlyreducethelatencyinsinglemuscletwi

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7、isaionoftheac—tionpotentialhereandashortersynapsesdelay．AccordinglyitwasspeculatedthatthestrengtheningexcitationWasalsoderivedfromthepromotionofCa2influxinnervefiberaxons，sodmtthecytoplasmCconcentrationincreased，leadingtoIll0reacetylcholinerelease．Keywords：托-apolyphen

8、ol；toad；sciaticnerve—gastroonemius；contractiontension；micro—end一Iatepotential茶多酚(11P)又名茶单宁、茶鞣质，是茶叶中多羟癌等[3_8]。wuLiang—yi等发现，1