7-Nitroindazole blocks conditioned place preference but not hyperactivity induced by morphine.
The effects of 7-nitroindazole (7-NI), a neural nitric oxide synthase (nNOS) inhibitor, on spontaneous locomotor activity, morphine-induced hyperactivity, acquisition of place conditioning and morphine-induced conditioned place preference (CPP) were evaluated in male mice. In experiment 1, animals treated with 7-NI (25, 50 and 100mg/kg), morphine (40 mg/kg) or morphine (40 mg/kg) plus 7-NI (25, 50 or 100mg/kg) were placed in an actimeter for 3h. In experiment 2, animals treated with the same drugs and doses were conditioned following an unbiased procedure. 7-NI did not affect the spontaneous locomotor activity or hyperactivity induced by morphine. However, the moderate and high doses of 7-NI produced conditioned place aversion (CPA) and the lowest dose blocked morphine-induced CPP. Our results suggest that nitric oxide is involved in the rewarding properties of morphine but not in its motor effects.
Manzanedo
Carmen
C
Departamento de Psicobiología, Facultad de Psicología, Universidad Complutense de Madrid, 28223 Madrid, Spain.
Aguilar
María A
MA
Rodríguez-Arias
Marta
M
Navarro
Miguel
M
Miñarro
José
J
D000701:Analgesics, Opioid / Q000037:antagonists & inhibitors* / Q000494:pharmacology*; D000818:Animals; D003216:Conditioning, Operant / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006948:Hyperkinesis / Q000139:chemically induced* / Q000523:psychology*; D007191:Indazoles / Q000494:pharmacology*; D008297:Male; D051379:Mice; D009020:Morphine / Q000037:antagonists & inhibitors* / Q000494:pharmacology*; D009043:Motor Activity / Q000187:drug effects; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors*; D052248:Nitric Oxide Synthase Type I; D012201:Reward
D000701:Analgesics, Opioid; D004791:Enzyme Inhibitors; D007191:Indazoles; D009020:Morphine; D019001:Nitric Oxide Synthase; D052248:Nitric Oxide Synthase Type I; C496321:Nos1 protein, mouse; C080122:7-nitroindazole