Hpm. Horikawa et al., DURATION OF CATALEPSY CORRELATES WITH INCREASED INTRASTRIATAL SULPIRIDE, European journal of pharmacology, 326(1), 1997, pp. 15-21
To investigate the mechanism underlying sulpiride-induced catalepsy, w
e simultaneously examined cataleptic behavior and the kinetics of the
dopamine receptor antagonist, sulpiride of dopamine, and the dopamine
metabolite 3,4-dihydroxyphenylacetic acid (DOPAC), using in vivo volta
mmetry. After intrastriatal administration of sulpiride to freely movi
ng rats, the levels increased, peaked at 20 min, and remained elevated
for more than 3 h. Sulpiride-induced cataleptic behavior also continu
ed for 3 h. Levels of DOPAC peaked 180 min after the injection and did
not return to baseline within the experimental period. Thus, the time
-course of cataleptic behavior correlated better with elevated extrace
llular levels of sulpiride than with that of DOPAC. These findings sug
gest that sulpiride induces catalepsy via a direct action.