Systemic and intrastriatal theophylline have opposite effects on dopamine and dopamine metabolites measured by intrastriatal microdialysis in the rat.
Using a model of intrastriatal microdialysis, we studied the effect of theophylline, an A1 and A2A adenosine receptor antagonist on striatal dopamine (DA) and DA metabolites. Systemic administration of theophylline (10 and 50 mg/kg) significantly reduced striatal extracellular (EC) levels of DA and its metabolites, 3,4-dihydroxyphenylacetic acid (DOPAC) and 4-hydroxy-3-methoxy-phenylacetic acid (HVA). Intrastriatal administration of theophylline (10(-2) M) significantly increased DA and its metabolites (DA1 + 120%; DOPAC, +28%; HVA, +30%). Contradictory effects of systemic and intrastriatal theophylline point to theophylline interactions with different receptors possibly at different locations.
Dethy
S
S
Service de Neurologie, ULB-Hôpital Erasme, Brussels, Belgium.
Laute
M A
MA
Togasaki
D M
DM
Przedborski
S
S
Damhaut
P
P
Thiry
P
P
Hildebrand
J
J
Goldman
S
S
D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000818:Animals; D003342:Corpus Striatum / Q000187:drug effects*; D004298:Dopamine / Q000378:metabolism*; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism; D008297:Male; D017551:Microdialysis; D051381:Rats; D017208:Rats, Wistar; D013806:Theophylline / Q000494:pharmacology*; D013997:Time Factors
D015102:3,4-Dihydroxyphenylacetic Acid; D006897:Hydroxyindoleacetic Acid; D013806:Theophylline; D004298:Dopamine