Hyposensitivity to amphetamine following exposure to chlorphenvinphos--protection by amphetamine preexposure.
We investigated the effect of an acute exposure to chlorphenvinphos (CVP), an organophosphate anticholinesterase, on amphetamine-induced open-field locomotion in rats. CVP was administered in a single i.p. dose of 1.0 mg/kg (1/10 of the LD50). All animals were challenged with 1.0 mg/kg amphetamine (AMPH) three weeks after the CVP exposure, i.e. after a time sufficient for acetylcholinesterase recovery. Some rats were also given AMPH three weeks before the CVP exposure. In rats challenged with AMPH only once after the CVP exposure, AMPH-induced open-field locomotion was significantly reduced. Such an effect was not observed in rats given AMPH three weeks before the CVP exposure. The results suggest that a single CVP exposure may result in persistent dopaminergic hyposensitivity, and that an amphetamine pretreatment may protect the rat against this effect.
Gralewicz
S
S
Department of Toxicology and Carcinogenesis, Nofer Institute of Occupational Medicine, Lódź, Poland. gralslaw@imp.lodz.pl.
Lutz
P
P
Szymczak
W
W
D000661:Amphetamine / Q000494:pharmacology*; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D000697:Central Nervous System Stimulants / Q000494:pharmacology*; D002709:Chlorfenvinphos / Q000494:pharmacology*; D002800:Cholinesterase Inhibitors / Q000494:pharmacology*; D004347:Drug Interactions; D005106:Exploratory Behavior / Q000187:drug effects; D008124:Locomotion / Q000187:drug effects*; D008297:Male; D051381:Rats; D017208:Rats, Wistar
D000697:Central Nervous System Stimulants; D002800:Cholinesterase Inhibitors; D000661:Amphetamine; D002709:Chlorfenvinphos