Parolaro D, Rubino T, Gori E, Massi P, Bendotti C, Patrini G, Marcozzi C, Parenti M
Institute of Pharmacology, Faculty of Sciences, University of Milan, Italy.
Eur J Pharmacol. 1993 Feb 15;244(3):211-22. doi: 10.1016/0922-4106(93)90146-z.
In situ hybridization histochemistry has been used to detect the basal distribution of mRNA encoding the alpha subunit of Gs, Go and Gi2 proteins throughout the rat brain. Based on these data we investigated the effect of chronic morphine on the content of these G protein alpha subunits mRNA. We observed an increase in the expression of alpha s and alpha o messages of chronically morphine-treated animals, while no changes were seen in alpha i2 mRNA. Specifically a 30% increase in expression for alpha s was seen only in the paraventricular nucleus of hypothalamus and a 20% elevation for alpha o was detected in the claustrum and endopiriform nucleus. Immunoblotting analysis was used to correlate the changes in alpha s and alpha o messages with equivalent changes in protein levels. Chronic morphine significantly increased alpha s amounts in the hypothalamus (70%), and produced a minor elevation (30%) in G alpha o levels in the olfactory area. Our results indicate that in discrete brain regions altered G protein expression is part of the adaptive changes underlying opiate tolerance.
原位杂交组织化学已用于检测大鼠脑中编码Gs、Go和Gi2蛋白α亚基的mRNA的基础分布。基于这些数据，我们研究了慢性吗啡对这些G蛋白α亚基mRNA含量的影响。我们观察到慢性吗啡处理动物的αs和αo信使表达增加，而αi2 mRNA未见变化。具体而言，仅在下丘脑室旁核中观察到αs表达增加30%，在屏状核和内梨状核中检测到αo升高20%。免疫印迹分析用于将αs和αo信使的变化与蛋白质水平的等效变化相关联。慢性吗啡显著增加了下丘脑中αs的含量（70%），并使嗅觉区域的Gαo水平略有升高（30%）。我们的结果表明，在离散的脑区中，G蛋白表达的改变是阿片耐受性潜在适应性变化的一部分。
