噻环乙胺对大鼠不同脑区内源性阿片肽含量的影响

Effect of Tiletamine on the Endogenous Opioid Peptides Content in Different Encephalic Regions of Rats

研究噻环乙胺麻醉下大鼠不同脑区内源性阿片肽含量的变化,探讨噻环乙胺中枢麻醉作用可能的机理。Wista大鼠128只,随机抽取8只为对照组,其余大鼠随机均分为5个试验组,分别用于测定L-Enk、M-Enk、β-EP、dynA和OFQ的含量;每个试验组又随机均分为麻醉组、恢复Ⅰ组和恢复Ⅱ组3个亚组。采用酶联免疫吸附试验(ELISA)测定各脑区内源性阿片肽的含量。结果显示腹腔内注射噻环乙胺25mg·kg-1后,麻醉组大鼠大脑皮层和丘脑内L-Enk、M-Enk、β-EP和dynA含量均显著增加(P<0.05或P<0.01),OFQ的含量显著降低(P<0.05或P<0.01);海马内L-Enk、M-Enk和β-EP含量均显著增加(P<0.05或P<0.01),dynA和OFQ的含量均无显著变化;脑干内M-Enk、β-EP和dynA含量均显著增加(P<0.05或P<0.01),OFQ的含量显著降低(P<0.05),L-Enk的含量无显著变化;恢复Ⅰ组和恢复Ⅱ组,上述各脑区内L-Enk、M-Enk、β-EP、dynA和OFQ的含量均恢复显著(P>0.05);麻醉全过程中,小脑内5种内源性阿片肽的含量均无显著变化(P>0.05)。结果提示噻环乙胺对不同脑区内源性阿片肽的影响,可能是其产生全麻作用的重要机理之一。噻环乙胺中枢麻醉作用,可能与增加大脑皮层和丘脑内L-Enk、M-Enk、β-EP和dynA,海马内L-Enk、M-Enk和β-EP和脑干内M-Enk、β-EP和dynA的含量,同时降低大脑皮层、丘脑和脑干内OFQ的含量有关。

To explain the possible molecular mechanisms of tiletamine anesthesia on the central nervous system by investigating the changes of endogenous opioid peptides content in different encephalic regions in rats.8 Wista rats were allocated randomly from 128 Wista rats as control group.The rest rats were divided randomly into L-Enk,M-Enk,β-EP,dynA and OFQ groups,and each group of animals were divided randomly into maintenance of anesthesia group,recovery from anesthesiaⅠgroup and recovery from anesthesiaⅡgroup.The content of 5 kinds of endogenous opioid peptides in different encephalic regions in rats were measured by Enzyme-Linked Immunosorbent Assays（ELISA）.The L-Enk,M-Enk,β-EP and dynA contents in the cerebral cortex and the thalamus in the anesthesia group were obviously increased as compared with control group（P0.05 or P0.01）,while the OFQ content was significantly decreased（P0.05 or P0.01）.The L-Enk,M-Enk and β-EP contents in the hippocampus were obviously increased as compared with control group（P0.05 or P0.01）,but neither the dynA nor OFQ contents were obviously changed.The M-Enk,β-EP and dynA contents in the brainstem were obviously increased as compared with control group（P0.05 or P0.01）,the OFQ content was obviously decreased（P0.05）,but the L-Enk content was not changed.In both of the recovery from anesthesiaⅠgroup and anesthesiaⅡgroup the L-Enk,M-Enk,β-EP,dynA and OFQ contents in the above encephalic regions were revived as compared with control group（P0.05）.The content of 5 kinds of endogenous opioid peptides in the cerebellum were not obviously changed in the process of general anesthesia of tiletamine.The results suggest that tiletamine anesthesia have an effect on the content of 5 kinds of endogenous opioid peptides in different encephalic regions.Tiletamine could increase the L-Enk,M-Enk,β-EP and dynA contents in both of the cerebral cortex and the thalamus,and increase the L-Enk,M-Enk and β-EP contents in the hippocampus,and M-Enk,β-EP and dynA contents in the brainstem,respectively,but decrease the OFQ content in the cerebral cortex,the thalamus and the brain stem.