褪黑素对猫丘脑后核内脏痛放电的影响Effect of melatonin on visceral pain discharges in the posterior thalamic group of nuclei in cats
邹丹,张桦,李经才
ZOU Dan 1; ZHANG Hua 2; LI Jing cai 1 (1.School of Pharmacy;
摘要(Abstract)：
目的观察静脉注射不同剂量褪黑素 (melatonin ,MT)对猫丘脑后核 (PO)诱发放电的影响及其存在的昼夜节律变化。方法本实验采用猫脑立体定位技术和玻璃微电极细胞外记录的方法 ,以刺激内脏大神经 (GSN)诱发PO单位放电作为内脏痛指标。结果静脉注射 1 0、1 5、2 0、2 5mg/kgMT对刺激GSN诱发的PO单簇放电均有抑制作用 ,随剂量的增大 ,抑制作用增强。对于相同的给药剂量 ( 1 5mg/kg) ,下午的镇痛时间明显较上午长 ,且存在统计学差异。 结论首次发现MT在丘脑后核水平参与抑制内脏痛 ,此抑制作用存在剂量依赖关系 ,并具有昼夜节律变化。
Objective In order to explore the effect induced by intravenous (iv.) melatonin (10,15,20,25 mg/kg) on the unit discharges evoked in the posterior group of thalamic nuclei(PO)and its diurnal charge. Methods As an indicator of visceral pain,the unit discharges of the neurous in PO was evoked by stimulating the preat splanchnie nerve(GSN). The extracellular recording method and stereotaxic techniques were used in this experiment. Results MT (10,15,20,25 mg/kg) could inhibite the one cluster discharges in PO evoked by stimulating GSN. This action was reinforced with the dose increse. To the equi analgesic dose(15 mg/kg),the analgesic duration was longer in the afternoon than in the forenoon, which exhibited statistical significance. Conclusions MT manifested a dose dependent analgesic action to visceral pain at thalamus level and it possessed a significant circadian rhythm.
关键词(KeyWords)：
褪黑素;镇痛;内脏痛;丘脑
melatonin; analgesia; visceralgia; thalamic
基金项目(Foundation): 国家自然科学基金资助项目 ( 395 70 82 0 )
作者(Authors):
邹丹,张桦,李经才
ZOU Dan 1; ZHANG Hua 2; LI Jing cai 1 (1.School of Pharmacy;
参考文献(References)：
- [1]魏伟,徐叔云.褪黑素的神经内分泌免疫作用及其应用前景[J].中国药理学通报,1997,13(3):196-200.
- [2]应水旺,张家驹.褪黑素对脑机能的影响[J].生理科学进展,1987,18(3):251-255.
- [3]SniderRS ,NiemerWT .Astereotanicatlasofthecatbrain[M].TheUniversityofChicagoPress,1961.25-30.
- [4]郑谦,张瑞德,袁淑德.内脏大神经传入冲动诱发猫丘脑后核单位放电的观察[J].针刺研究,1983,2:213-217.
- [5]周敏明,俞昌喜,曹小定.褪黑素加强电针镇痛效应及其与中枢β内啡肽的关系[A].中国神经科学学会编著.中国神经科学学会第二届代表大会暨第三届全国学术会议论文摘要汇编[C].北京医科大学,1999.204.
- [6]邹冈,易庆成,吴时祥.脑啡肽在针刺镇痛中的作用:放射免疫测定[J].中国科学,1980(5):492-499.
- [7]BasbaumAI,FieldsHL .Endogenouspaincontrolmech anisms:reviewandhypothesis[J].AnnNeurol,1978(4):451-462.
- [8]VacasMI,CardinaliDP .Diurnalchangesinmelatoninbindingsiteofhamsterandratbrain[J].NeurosciLett,1979,15(2-3):259-263.