Effects of amphetamine and sydnocarb on dopamine release and free radical generation in rat striatum

Microdialysis technique was used to compare the effects of four repeated in traperitoneal administrations of two psychostimulant drugs, D-amphetamine a nd sydnocarb, at the equimolar doses 5 and 23.8 mg/kg, respectively, on the extracellular level of dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPA C) and hydroxyl radicals (OH) in the dorsal striatum of freely moving 3-mon th-old male Wistar rats 250-300 g in weight. D-Amphetamine caused immediate increase of DA concentration up to 950% with quick decline towards baselin e values thereafter, followed by much less increase after further injection s. Sydnocarb elicited moderate elevation in DA level achieving 400% after t he fourth injection. D-Amphetamine induced deep decrease in DOPAC concentra tion, while sydnocarb caused its increase after the first and second dosing . Both drugs enhanced generation of OH, the effect Of D-amphetamine was mor e pronounced. D-Amphetamine induced more intensive stereotyped behavior in rats compare to sydnocarb. It is concluded that the psychostimulant action of sydnocarb is accompanied by facilitation of the central dopaminergic tra nsmission in rat neostriatum and followed by less pronounced neurotoxic eff ect than that of D-ampletamine. (C) 2001 Elsevier Science Inc. All rights r eserved.