Effects of flunarizine on dopamine dependent behaviours in rats.
1. Radio-ligand binding study has demonstrated that flunarizine has a high affinity for the rat striatal D 2 dopamine (DA) receptors. 2. In the present behavioural study conducted in rats it was observed that flunarizine, unlike the postsynaptic striatal D 2 DA receptor agonist apomorphine, did not induce stereotyped behaviour (SB) in rats. This indicates that flunarizine does not act as an agonist at the postsynaptic striatal D 2 DA receptors. 3. Flunarizine however, like the postsynaptic striatal D 2 DA receptor antagonist haloperiodal, inhibited the conditioned avoidance response, induced catalepsy and antagonized the SB induced by the DA agonists apomorphine and methamphetamine. 4. Our findings indicate that flunarizine acts as a postsynaptic striatal D 2 DA receptor antagonist.
Moorthy
N S
NS
Department of Pharmacology, Krishna Institute of Medical Sciences.
Balsara
J J
JJ
D000818:Animals; D001058:Apomorphine / Q000494:pharmacology; D001362:Avoidance Learning / Q000187:drug effects*; D001522:Behavior, Animal / Q000187:drug effects*; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D002375:Catalepsy / Q000139:chemically induced*; D003342:Corpus Striatum / Q000187:drug effects; D004298:Dopamine / Q000494:pharmacology*; D065127:Dopamine D2 Receptor Antagonists; D004359:Drug Therapy, Combination; D005444:Flunarizine / Q000494:pharmacology*; D007274:Injections, Intraperitoneal; D008297:Male; D008694:Methamphetamine / Q000494:pharmacology; D051381:Rats; D013239:Stereotyped Behavior / Q000187:drug effects*
D002121:Calcium Channel Blockers; D065127:Dopamine D2 Receptor Antagonists; D008694:Methamphetamine; D001058:Apomorphine; D005444:Flunarizine; D004298:Dopamine