Effects of salicylic acid on basal and amphetamine-induced striatal dop amine release: A microdialysis study

Salicylic acid (SA) is currently employed by many investigators as a tool to investigate hydroxyl free radical formation in in vivo systems via the quantitation of the SA products 2,3-dihydroxybenzoic acid (DHBA) and 2,5-DHBA We investigated the effects of SA on basal and damphetamine (AMP) induced striatal dopamine (DA) release using in vivo microdialysis. After a 3 mm loop-design microdialysis probe was stereotaxically implanted into the striatum of urethane-anesthetized rats, and following 2 hrs stabilization, 3 basal dialysates were collected. SA (0, 30, 100, 300 mg/kg, i.p.) was then administered followed 30 min later by AMP (5 mg/kg, i p.). With the exception of the highest dose of SA, no changes in DA were observed prior to AMP administration SA (300 mg/kg) significantly increased DA levels at 30 min (49%) prior to AMP administration. AMP increased DA by 40-57 fold in all groups of animals. SA in any dose failed to significantly alter the increase in DA levels in response to AMP at 30 or 45 min These results demonstrate the ability of SA to modify basal DA levels, but only at high doses, while having no effect on AMP-stimulated release.