Cholecystokinin modulation of apomorphine- or amphetamine-induced stereotypy in rats: opposite effects.
Stereotyped behavior can be induced by the dopamine agonist apomorphine or by the releasing agent amphetamine. Cholecystokinin influence on dopamine-mediated behaviors has been extensively studied but a real controversy remains. Our purpose was to further characterize the dopamine-cholecystokinin interaction in apomorphine- and amphetamine-induced stereotyped behavior using sulphated cholecystokinin octapeptide (CCK8) and cholecystokinin tetrapeptide (CCK4) treatments. The results showed that CCK8 decreases apomorphine-induced stereotyped behavior and CCK4 has no effect. CCK4 and CCK8 increased the amphetamine-induced stereotyped behavior; CCK4 was more effective. The results confirm the opposite modulation of apomorphine or amphetamine-induced stereotyped behavior by CCK. These data suggest that this modulation is mediated by both CCK receptors on apomorphine-induced and only by CCK(2) receptors on amphetamine-induced stereotyped behavior.
Tieppo
C A
CA
Department of Physiological Sciences, Medical School of Santa Casa de São Paulo, 01277-900 São Paulo-SP, Brazil. catieppo@hotmail.com
Felicio
L F
LF
Nasello
A G
AG
D000662:Amphetamines / Q000494:pharmacology*; D000818:Animals; D001058:Apomorphine / Q000494:pharmacology*; D002766:Cholecystokinin / Q000494:pharmacology*; D004298:Dopamine / Q000378:metabolism*; D018491:Dopamine Agonists / Q000494:pharmacology*; D004347:Drug Interactions; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D011949:Receptors, Cholecystokinin / Q000378:metabolism; D012844:Sincalide / Q000494:pharmacology; D013569:Synapses / Q000187:drug effects; D013758:Tetragastrin / Q000494:pharmacology; D013997:Time Factors
D000662:Amphetamines; D018491:Dopamine Agonists; D011949:Receptors, Cholecystokinin; D013758:Tetragastrin; D002766:Cholecystokinin; D012844:Sincalide; D001058:Apomorphine; D004298:Dopamine