The effect of CP 55,940 {(-)-cis-3-[2-hydroxy-4-(1,1-dimethylheptyl)phenyl]-trans-4- (3-hydroxypropyl)cyclo-hesanol}, heroin and etonitazene on intracerebroventricular (i.c.v.) self-administration in a free-choice procedure was evaluated in rats. Animals were trained in 1-h daily sessions with a continuous reinforcement schedule to press two active levers to obtain the vehicle of each drug. Then, when a stable baseline was reached, each drug could be self-administered by pressing the lever found to be less preferred during training, while the vehicle came from the other. The number of bar pressings associated with the delivery of increasing unit doses of CP 55,940 (0.1, 0.2, 0.4, 0.8, 1.6 μg/2 μl/infusion), heroin (0.125, 0.25, 0.5, 1, 2 μg/2 μl/infusion) or etonitazene (0.1-0.2-0.5-1 μg/2 μl/infusion) and with the delivery of the corresponding vehicle was fitted by symmetrical parabolas. The mean drug intake was linearly related to the log of self-administered drugs. Pretreatment with SR141716A [N-piperidino-5-(4-chlorophenyl)1-(2,4-dichloro-phenyl)-4-methylpyrazole-3- carboxamide] (0.5 mg/kg) or naloxone HCl (2 mg/kg/i.p.) 15 min before each daily session reduced the self-administration of both CP 55,940 and heroin. The combination of CP 55,940 with heroin or etonitazene reduced the number of drug-associated lever pressings compared to that obtained with the maximal reinforcing unit dose of each drug alone. These findings suggest there may be a strong interaction between opioids and the cannabinoid system.

Intracerebral self-administration of the cannabinoid receptor agonist CP 55,940 in the rat : interaction with the opioid system / D. BRAIDA, M. POZZI, D. PAROLARO, M. SALA. - In: EUROPEAN JOURNAL OF PHARMACOLOGY. - ISSN 0014-2999. - 413:2-3(2001), pp. 227-234. [10.1016/S0014-2999(01)00766-X]

Intracerebral self-administration of the cannabinoid receptor agonist CP 55,940 in the rat : interaction with the opioid system

D. BRAIDA;D. PAROLARO;M. SALA
2001

Abstract

The effect of CP 55,940 {(-)-cis-3-[2-hydroxy-4-(1,1-dimethylheptyl)phenyl]-trans-4- (3-hydroxypropyl)cyclo-hesanol}, heroin and etonitazene on intracerebroventricular (i.c.v.) self-administration in a free-choice procedure was evaluated in rats. Animals were trained in 1-h daily sessions with a continuous reinforcement schedule to press two active levers to obtain the vehicle of each drug. Then, when a stable baseline was reached, each drug could be self-administered by pressing the lever found to be less preferred during training, while the vehicle came from the other. The number of bar pressings associated with the delivery of increasing unit doses of CP 55,940 (0.1, 0.2, 0.4, 0.8, 1.6 μg/2 μl/infusion), heroin (0.125, 0.25, 0.5, 1, 2 μg/2 μl/infusion) or etonitazene (0.1-0.2-0.5-1 μg/2 μl/infusion) and with the delivery of the corresponding vehicle was fitted by symmetrical parabolas. The mean drug intake was linearly related to the log of self-administered drugs. Pretreatment with SR141716A [N-piperidino-5-(4-chlorophenyl)1-(2,4-dichloro-phenyl)-4-methylpyrazole-3- carboxamide] (0.5 mg/kg) or naloxone HCl (2 mg/kg/i.p.) 15 min before each daily session reduced the self-administration of both CP 55,940 and heroin. The combination of CP 55,940 with heroin or etonitazene reduced the number of drug-associated lever pressings compared to that obtained with the maximal reinforcing unit dose of each drug alone. These findings suggest there may be a strong interaction between opioids and the cannabinoid system.
Settore BIO/14 - Farmacologia
EUROPEAN JOURNAL OF PHARMACOLOGY
Article (author)
File in questo prodotto:
Non ci sono file associati a questo prodotto.
Pubblicazioni consigliate

Caricamento pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/2434/184744
Citazioni
  • ???jsp.display-item.citation.pmc??? 24
  • Scopus 101
  • ???jsp.display-item.citation.isi??? 93
social impact