Effects of amphetamine challenge on local cerebral glucose utilization after chronic dopamine D1 and D2 receptor...

Repeated amphetamine administration can cause an augmentation of regional cerebral metabolic activity. This study analyzed the regional cerebral metabolic changes which occurred in rats after pretreatment with the selective dopamine D1 and D2 receptor agonists, (+/-)SKF 38393 ((+/-)-2,3,4,5-tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine HCl) and quinpirole (trans-(-)-4aR-4,4a,5,6,7,8,8a,9-octahydro-5-propyl-1H-pyrazolo(3, 4-g)quinoline), as measured by the 2-[14C]deoxyglucose method. The results showed selective metabolic augmentation in rats pretreated with SKF 38393 but not in those pretreated with quinpirole alone or with quinpirole in combination with SKF 38393. These findings demonstrated that dopamine D1 receptors may play a critical role in the development of metabolic augmentation after repeated stimulant administration.