Duration of catalepsy correlates with increased intrastriatal sulpiride.
To investigate the mechanism underlying sulpiride-induced catalepsy, we 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 voltammetry. After intrastriatal administration of sulpiride to freely moving rats, the levels increased, peaked at 20 min, and remained elevated for more than 3 h. Sulpiride-induced cataleptic behavior also continued 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 extracellular levels of sulpiride than with that of DOPAC. These findings suggest that sulpiride induces catalepsy via a direct action.
Horikawa
H P
HP
Department of Molecular Neurobiology, Brain Research Institute, Niigata University, Asahimachi, Japan. hiroshi@bri.niigata-u.ac.jp
Nakazato
T
T
Hikosaka
O
O
D015655:1-Methyl-4-phenylpyridinium / Q000378:metabolism; D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000818:Animals; D002375:Catalepsy / Q000139:chemically induced* / Q000503:physiopathology; D004298:Dopamine / Q000378:metabolism; D015259:Dopamine Agents / Q000378:metabolism; D018492:Dopamine Antagonists / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000494:pharmacology*; D065127:Dopamine D2 Receptor Antagonists; D004563:Electrochemistry; D006719:Homovanillic Acid / Q000378:metabolism; D008297:Male; D008845:Microinjections; D017072:Neostriatum / Q000378:metabolism / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013469:Sulpiride / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000494:pharmacology*; D013997:Time Factors
D015259:Dopamine Agents; D018492:Dopamine Antagonists; D065127:Dopamine D2 Receptor Antagonists; D015102:3,4-Dihydroxyphenylacetic Acid; D013469:Sulpiride; D015655:1-Methyl-4-phenylpyridinium; D004298:Dopamine; D006719:Homovanillic Acid