Chronic cocaine produces decreases in N/OFQ peptide levels in select rat brain regions.
The interaction of opioids and stimulants is well established; however, the mechanisms that underlie the role that opioid receptors play in psychostimulant action are not. Nociceptin/orphaninFQ (N/OFQ), the endogenous agonist at NOP receptors, attenuates the behavioral effects of cocaine. The effects of cocaine on N/OFQ were examined in rats using immunoautoradiographic and RIA techniques. Chronic administration of cocaine decreased N/OFQ in medial regions of the caudate putamen, the nucleus accumbens shell, and the substantia nigra. These studies show that N/OFQ levels are altered by treatment with cocaine. Furthermore, the changes in N/OFQ parallel those seen for kappa-opioid receptors, suggesting that the interactions between cocaine and these systems might be similar.
Romualdi
Patrizia
P
Department of Pharmacology, University of Bologna, 40126 Bologna, Italy. patrizia.romualdi@unibo.it
Di Benedetto
Manuela
M
D'Addario
Claudio
C
Collins
Stephanie L
SL
Wade
Dean
D
Candeletti
Sanzio
S
Izenwasser
Sari
S
D000818:Animals; D002421:Caudate Nucleus / Q000187:drug effects / Q000378:metabolism; D000697:Central Nervous System Stimulants / Q000008:administration & dosage / Q000494:pharmacology; D003042:Cocaine / Q000008:administration & dosage / Q000494:pharmacology; D009714:Nucleus Accumbens / Q000187:drug effects / Q000378:metabolism; D018847:Opioid Peptides / Q000378:metabolism*; D011699:Putamen / Q000187:drug effects / Q000378:metabolism; D011863:Radioimmunoassay; D051381:Rats; D017207:Rats, Sprague-Dawley; D013378:Substantia Nigra / Q000187:drug effects / Q000378:metabolism; D000097629:Nociceptin
D000697:Central Nervous System Stimulants; D003042:Cocaine; D018847:Opioid Peptides; D000097629:Nociceptin