The anti-nociceptive effect of reserpine and haloperidol mediated by the nigro-striatal system: antagonism by naloxone.
Reserpine (10 mg/kg) and haloperidol (2 mg/kg) injected intraperitoneally increased the reaction time of the tail-flick response in intact but not in pre-nigrally decerebrate or spinal rats. The antinociceptive effect of both drugs was antagonized by intraperitoneal injections of dopa (100 mg/kg), apomorphine (2 mg/kg) or naloxone (1 mg/kg) as well as by bilateral micro-injections into the caudate nuclei of apomorphine (100 microgram and 20 microgram) and naloxone (10 microgram). It is concluded that the nigrostriatal feedback system is involved in the anti-nociceptive effect of reserpine and haloperidol.
D000700:Analgesics; D000818:Animals; D003342:Corpus Striatum / Q000502:physiology*; D005260:Female; D006220:Haloperidol / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D009020:Morphine / Q000494:pharmacology; D009270:Naloxone / Q000494:pharmacology*; D051381:Rats; D011930:Reaction Time / Q000187:drug effects; D012110:Reserpine / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D013378:Substantia Nigra / Q000502:physiology*
D000700:Analgesics; D009270:Naloxone; D009020:Morphine; D012110:Reserpine; D006220:Haloperidol