Increased in vivo [¹¹C]raclopride binding to brain dopamine receptors in amphetamine-treated rats

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• 作者：Michael R. Kilbourn^a ; ^{mkilbour@umich.edu} ; Edward F. Domino^b
• 关键词：Raclopride ; Amphetamine ; Sensitization
• 刊名：European Journal of Pharmacology
• 出版年：2011
• 出版时间：11 March 2011
• 年：2011
• 卷：654
• 期：3
• 页码：254-257
• 全文大小：153 K

文摘

The hypothesis that repeated daily doses of amphetamine increases the number of available dopamine D₂ receptors in vivo in rat striatum, and may enhance the response to subsequent amphetamine challenge doses, was examined. The in vivo binding potentials of [¹¹C]raclopride, a D₂ receptor antagonist, were determined in male CD-1 rats under five conditions: (1) drug-naïve with saline challenge, (2) drug naïve with 5 mg/kg amphetamine challenge, (3) amphetamine-dosed (five daily repeated s.c. doses of 5 mg/kg amphetamine) and saline challenge, (4) amphetamine-dosed and amphetamine challenge, and (5) saline treated (five daily repeated s.c. doses) and saline challenged. Radiotracer studies in amphetamine-dosed animals were done after a 10-day drug free interval. In the amphetamine-dosed group the baseline [¹¹C]raclopride binding was increased by 63 % compared to saline-treated controls. The response to an amphetamine challenge, evidenced by a reduction of [¹¹C]raclopride binding, was doubled in amphetamine-dosed animals (40 % ) compared to drug-naïve controls (20 % ). These results support increased baseline in vivo dopamine D₂ receptor antagonist radioligand binding after repeated amphetamine administration in rats.