Levels of dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC), ascorbic acid (AA) and dehydroascorbic acid (DHAA) were determined by HPLC in the striatum of male Wistar rats after single or repeated injections of apomorphine (1 mg/kg/day s.c.) and/or haloperidol (1 mg/kg/day i.p.), and 24 h after the last drug administration. Apomorphine significantly reduced the DOPAC/DA ratio and increased the DHAA/AA ratio; these ratio changes were significantly correlated (r = -0.9969, P less than 0.0005). Haloperidol greatly increased the DOPAC/DA ratio; the DHAA/AA ratio was also slightly increased, but there was no significant correlation. When apomorphine was associated with haloperidol, the resulting DOPAC/DA ratio was significantly lower than after haloperidol alone; the DHAA/AA ratio was also significantly reduced in contrast to the effect of apomorphine alone. It is concluded that a non-selective DA receptor activation mediates, in a correlated way, both the inhibition of DA turnover and the increase of AA oxidation in the rat striatum.
Investigations into the relationship between the dopaminergic system and ascorbic acid in rat striatum / Desole, Maria Speranza; Miele, M; Enrico, Paolo; Esposito, G; Fresu, L; DE NATALE, G; Miele, E.. - In: NEUROSCIENCE LETTERS. - ISSN 0304-3940. - 127(1):1(1991), pp. 34-38.