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James R Shoblock,
Natalie Welty,
Leah Aluisio,
Ian Fraser,
S Timothy Motley,
Kirsten Morton,
James Palmer,
Pascal Bonaventure,
Nicholas I Carruthers,
Timothy W Lovenberg, Jamin Boggs,
Ruggero Galici
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ABSTRACT: Orexin-1 receptor antagonists have been shown to block the reinforcing effects of drugs of abuse and food. However, whether blockade of orexin-2 receptor has similar effects has not been determined. We have recently described the in vitro and in vivo effects of JNJ-10397049, a selective and brain penetrant orexin-2 receptor antagonist.
The goal of these studies was to evaluate whether systemic administration of JNJ-10397049 blocks the rewarding effects of ethanol and reverses ethanol withdrawal in rodents. As a comparison, SB-408124, a selective orexin-1 receptor antagonist, was also evaluated.
Rats were trained to orally self-administer ethanol (8% v/v) or saccharin (0.1% v/v) under a fixed-ratio 3 schedule of reinforcement. A separate group of rats received a liquid diet of ethanol (8% v/v) and withdrawal signs were evaluated 4 h after ethanol discontinuation. In addition, ethanol-induced increases in extracellular dopamine levels in the nucleus accumbens were tested. In separate experiments, the acquisition, expression, and reinstatement of conditioned place preference (CPP) were evaluated in mice.
Our results indicate that JNJ-10397049 (1, 3, and 10 mg/kg, sc) dose-dependently reduced ethanol self-administration without changing saccharin self-administration, dopamine levels, or withdrawal signs in rats. Treatment with JNJ-10397049 (10 mg/kg, sc) attenuated the acquisition, expression, and reinstatement of ethanol CPP and ethanol-induced hyperactivity in mice. Surprisingly, SB-408124 (3, 10 and 30 mg/kg, sc) did not have any effect in these procedures.
Collectively, these results indicate, for the first time, that blockade of orexin-2 receptors is effective in reducing the reinforcing effects of ethanol.
Psychopharmacologia 12/2010; 215(1):191-203. · 4.08 Impact Factor
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Ruggero Galici,
Amir H Rezvani,
Leah Aluisio,
Brian Lord,
Edward D Levin,
Ian Fraser, Jamin Boggs,
Natalie Welty,
James R Shoblock,
S Timothy Motley,
Michael A Letavic,
Nicholas I Carruthers,
Christine Dugovic,
Timothy W Lovenberg,
Pascal Bonaventure
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ABSTRACT: A few recent studies suggest that brain histamine levels and signaling via H(3) receptors play an important role in modulation of alcohol stimulation and reward in rodents.
The present study characterized the effects of a novel, selective, and brain penetrant H(3) receptor antagonist (JNJ-39220675) on the reinforcing effects of alcohol in rats.
The effect of JNJ-39220675 on alcohol intake and alcohol relapse-like behavior was evaluated in selectively bred alcohol-preferring (P) rats using the standard two-bottle choice method. The compound was also tested on operant alcohol self administration in non-dependent rats and on alcohol-induced ataxia using the rotarod apparatus. In addition, alcohol-induced dopamine release in the nucleus accumbens was tested in freely moving rats.
Subcutaneous administration of the selective H(3) receptor antagonist dose-dependently reduced both alcohol intake and preference in alcohol-preferring rats. JNJ-39220675 also reduced alcohol preference in the same strain of rats following a 3-day alcohol deprivation. The compound significantly and dose-dependently reduced alcohol self-administration without changing saccharin self-administration in alcohol non-dependent rats. Furthermore, the compound did not change the ataxic effects of alcohol, alcohol elimination rate, nor alcohol-induced dopamine release in nucleus accumbens.
These results indicate that blockade of H(3) receptor should be considered as a new attractive mechanism for the treatment of alcoholism.
Psychopharmacologia 11/2010; 214(4):829-41. · 4.08 Impact Factor
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ABSTRACT: Norfluoxetine is the most important active metabolite of the widely used antidepressant fluoxetine. Although the pharmacokinetics/pharmacodynamics (PK/PD) relationship and neurochemical profile of fluoxetine is well characterized in human and in animals, little is known about the effect of its metabolite. The aim of this study was to characterize extracellular level of serotonin (5-hydroxytryptamine, 5-HT)-time profile of norfluoxetine after acute administration over 18 h post dose and to establish the relationship between this pharmacodynamic (PD) profile and its pharmacokinetic (PK) properties. Following subcutaneous administration of fluoxetine in rats, plasma and brain PK of fluoxetine and norfluoxetine were monitored respectively by liquid chromatography/tandem mass spectrometry (LC/MS/MS). The extracellular level of 5-HT in the frontal cortex was measured by microdialysis as a PD endpoint. Norfluoxetine when directly administrated to rats caused a significant increase in extracellular level of 5-HT in the frontal cortex and maintained for 18 h. This result is correlated well with higher plasma and brain concentration and longer plasma and brain retention time of norfluoxetine. Our results showed that norfluoxetine contributes to 5-HT transporter inhibition and extends fluoxetine efficacy.
Pharmacology Biochemistry and Behavior 06/2009; 92(3):469-73. · 2.53 Impact Factor
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Pharmacology Biochemistry and Behavior 01/2009; · 2.53 Impact Factor
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Leah Aluisio,
Brian Lord,
Ann J Barbier,
Ian C Fraser,
Sandy J Wilson, Jamin Boggs,
Lisa K Dvorak,
Michael A Letavic,
Bruce E Maryanoff,
Nicholas I Carruthers,
Pascal Bonaventure,
Timothy W Lovenberg
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ABSTRACT: Triple reuptake inhibitors, which block the serotonin transporter (SERT), norepinephrine transporter (NET) and dopamine transporter (DAT) in the central nervous system have been described as therapeutic alternatives for classical selective serotonin reuptake inhibitors, with advantages due to their multiple mechanisms of action. JNJ-7925476 (trans-6-(4-ethynylphenyl)-1,2,3,5,6,10b-hexahydropyrrolo[2,1-a]isoquinoline) is a selective and potent inhibitor of the SERT, NET, and DAT (K(i)=0.9, 17 and 5.2 nM, respectively). Following subcutaneous dosing in rat, JNJ-7925476 was rapidly absorbed into the plasma, and drug concentrations in the brain tracked with those in the plasma but were 7-fold higher. The ED(50) values for JNJ-7925476 occupancy of the SERT, NET, and DAT in rat brain were 0.18, 0.09 and 2.4 mg/kg, respectively. JNJ-7925476 (0.1-10 mg/kg, s.c.) rapidly induced a robust, dose-dependent increase in extracellular serotonin, dopamine, and norepinephrine levels in rat cerebral cortex. The compound also showed potent antidepressant-like activity in the mouse tail suspension test (ED(50)=0.3 mg/kg, i.p.). These results demonstrate that JNJ-7925476 is a triple reuptake inhibitor with in-vivo efficacy in biochemical and behavioral models of depression.
European Journal of Pharmacology 07/2008; 587(1-3):141-6. · 2.52 Impact Factor
