褪黑素对吗啡戒断小鼠下丘脑弓状核和中脑导水管周围灰质中β-内啡肽含量的影响  

Effect of melatonin on the content of β-endorphin in the hypothalamic arcuate nucleus and periaqueductal grey of midbrain in morphine withdrawal mice

作　　者：魏义明[1] 许盈[1] 俞昌喜[1] 

机构地区：[1]福建医科大学药理学系,福州350004

出　　处：《生理学报》2007年第6期765-769,共5页Acta Physiologica Sinica

基　　金：This work was supported by the Project of Science and Technology Exploitation of Fujian Province;China(No.2005D073);the Natural Science Foundation of Fujian Province;China(No.C0410018);the Project of Science and Technology Bureau of Fujian Province;China(No.2006F5046)

摘　　要：本文在观察腹腔注射褪黑素(melatonin,MEL)拮抗吗啡依赖小鼠纳洛酮催促戒断反应的同时,采用放射免疫分析法、免疫组织化学法,结合计算机图像处理技术,测定其对小鼠中脑导水管周围灰质(periaqueductal grey,PAG)、下丘脑弓状核(hypothalamic arcuate nucleus,Arc)中β-内啡肽(β-endorphin,β-EP)含量的影响。结果表明,MEL(80 mg/Kg体重)显著抑制吗啡依赖小鼠戒断反应(P<0.05)的同时,可显著增加其中脑PAG中β-EP含量(p<0.05),减弱Arc中β-EP样免疫阳性反应强度(P<0.05)。上述结果提示,MEL可提高吗啡戒断小鼠中脑PAG中β-EP含量,降低Arc中β-EP含量。The present study was undertaken to investigate the effect of melatonin on the content of β-endorphin （β-EP） in the hypothalamic arcuate nucleus （Arc） and periaqueductal grey （PAG） of midbrain in morphine withdrawal mice. Male Kunming mice were injected subcutaneously （s.c.） with an increasing dose of morphine continuously for 8 d to establish morphine dependence model. Withdrawal response was induced by naloxone （3 mg/kg body weight, s.c.）. The potency of withdrawal response was evaluated according to the jumping times and body weight loss. Ninty minutes prior to the precipitation of naloxone, 80 mg/kg body weight of melatonin （MEL） was injected intraperitoneally （i.p.） to observe its antagonistic effect on the withdrawal response in morphine-dependent mice. After behavioral observation, radioimmunoassay was used to determine the content of β-EP in the PAG of midbrain, and immunohistochemical assay was used to observe the intensity of β-EP-like immunoreactivity in the Arc in mice. It was shown that MEL inhibited the naloxone-precipitated withdrawal responses in mice significantly （P〈0.05）. In the meantime, MEL increased the content of β-EP in the PAG of midbrain significantly （P〈0.05） and attenuated the intensity of β-EP-like immunoreactivity in the Arc in mice （P〈0.05）. The results suggest that MEL increases the content of β-EP in the PAG of midbrain, decrease the content of β-EP in the Arc in morphine withdrawal mice.

关 键 词：褪黑素 吗啡依赖 戒断反应 下丘脑弓状核 中脑导水管周围灰质 β-内啡肽 

分 类 号：Q42[生物学—神经生物学]