Naloxone does not alter amphetamine-induced rotational behavior or striatal dopamine levels of nigrally-lesioned rats.
Previous studies on rats have shown that the opioid antagonist naloxone attenuates amphetamine-induced stimulation of locomotor activity and increases in extracellular dopamine in the brain. However, in this study, naloxone did not attenuate amphetamine-induced rotational behavior or increases of extracellular dopamine in the intact striatum of nigrally-lesioned rats. These results suggests differences in the way in which endogenous opioids contribute to the behavioral and neurochemical effects of amphetamine in nigrally-lesioned compared to intact rats.
Kimmel
H L
HL
Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322, USA. hlkimme@emory.edu
Schad
C A
CA
Justice
J B
JB
Holtzman
S G
SG
D000661:Amphetamine / Q000494:pharmacology*; D000818:Animals; D000697:Central Nervous System Stimulants / Q000494:pharmacology*; D003042:Cocaine / Q000494:pharmacology; D003342:Corpus Striatum / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism*; D018765:Dopamine Uptake Inhibitors / Q000494:pharmacology*; D008297:Male; D009270:Naloxone / Q000494:pharmacology*; D009292:Narcotic Antagonists / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012399:Rotation; D013239:Stereotyped Behavior / Q000187:drug effects*; D013378:Substantia Nigra / Q000502:physiology*
D000697:Central Nervous System Stimulants; D018765:Dopamine Uptake Inhibitors; D009292:Narcotic Antagonists; D009270:Naloxone; D000661:Amphetamine; D003042:Cocaine; D004298:Dopamine