热应激对大鼠纹状体多巴胺介导的磷脂酰肌醇信号系统的影响  

Effects of Heat Stress on DA Mediated PI Signal Transduction System in Rat Striatum

作　　者：赵亚丽[1] 邢成[2] 吕志忠[2] 王鲁明[2] 李建栋[2] 赵永岐[2] 

机构地区：[1]航天医学工程研究所,北京100094 [2]军事医学科学院基础医学研究所,北京100850

出　　处：《航天医学与医学工程》2001年第2期116-119,共4页Space Medicine & Medical Engineering

基　　金：自然科学基金资助项目!( 3 967962 7)

摘　　要：目的探讨热应激对纹状体多巴胺 (DA)介导的磷脂酰肌醇 (PI)信号转导系统的影响。方法将雄性Wistar大鼠随机分为对照组和热应激组 ,大鼠在加热小仓中受热 ,达到设定肛温 (Tr)时即刻取出 ,取纹状体 ,分别用荧光分光光度法、酸碱滴定法、高压液相法和Fura 2 /AM荧光标记法测DA含量、PLA2活性、PI含量和 [Ca2 +]i。结果 41 .0℃Tr以上时 ,随Tr升高DA含量有持续增高趋势 ,并在 43.0℃Tr时 ,比对照显著增加 ;在 41 .0℃Tr时 ,PLA2 活性较对照显著增强 ,热应激组PI含量显著低于对照 ;在42 .0℃Tr时 ,[Ca2 +]i 比对照显著增高 ,热应激前 1h给予D2R拮抗剂氯氮平 ,则可减弱热应激引起的[Ca2 +]i 的升高 ,并延长肛温到达 42 .0℃的时间。结论热应激可能激动了DA介导的PI信号转导系统 ,[Ca2 +]i 升高可能经D2R介导 ,用D2R拮抗剂 ,可以提高机体耐热性。Objective To study the effects of heat stress on dopamine(DA) and related phosphatidylinositol(PI) signal transduction system members:PLA 2,PI,Ca 2+ in rat striatum. Method Male Wistar rats were randomly divided into control group and heat stressed group. Heat stressed rats were placed in small hot chambers and taken out as soon as their rectal temperatures (Tr) reached the preset temperature. Then the animals were killed and their striatums were taken out. Fluorospectrophotometry, HPLC, Fura 2/AM fluoresence labelled method and acidalkaline titration were used to measure the content of DA,PI,[Ca 2+ ] i and the enzyme activity of PLA 2. Result During heat stress, when rats’ Tr reached 41.0℃ or higher, with increase of Tr, DA content increased continuously. When Tr=43.0℃, DA content was significantly higher than control. When Tr=41.0℃ PLA 2 activity was higher than control significantly, PI content of heat stressed group decreased significantly than control.[Ca 2+ ] i increased significantly when Tr=42.0℃ as compared with control. But if DA receptor2 (D2R) antagonist was given an hour before heat stress,[Ca 2+ ] i decreased and Tr took a longer time to get to 42.0℃. Conclusion During heat stress, DA mediated PI signal transduction system was activated. The increase of [Ca 2+ ] i might be mediated by D2R, and D2R antagonist may improve thermotolerance.

关 键 词：热应激 纹状体 PI信号转导系统 多巴胺 体温调节 

分 类 号：R338.2[医药卫生—人体生理学] R852.51[医药卫生—基础医学]