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- Domi, Esi, et al.
(författare)
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Further evidence for the involvement of the PPAR gamma system on alcohol intake and sensitivity in rodents
- 2020
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Ingår i: Psychopharmacology. - : Springer Science and Business Media LLC. - 0033-3158 .- 1432-2072. ; 237, s. 2983-2992
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Tidskriftsartikel (refereegranskat)abstract
- Rationale Peroxisome Proliferator Activator receptors (PPARs) are intracellular receptors that function as transcription factors, which regulate specific metabolic and inflammatory processes. PPARs are broadly distributed in the body and are also expressed in the central nervous system, especially in areas involved in addiction-related behavioral responses. Recent studies support a role of PPARs in alcoholism and pioglitazone: a PPAR gamma agonist used for treatment of type 2 diabetes showed efficacy in reducing alcohol drinking, stress-induced relapse, and alcohol withdrawal syndrome in rats. Objectives and Methods In the current work, we tested the pharmacological effects of pioglitazone on binge-like alcohol consumption using an intermittent two-bottle choice paradigm in Wistar rats and on the "drinking in the dark" (DID) model in mice with selective deletion of PPAR gamma in neurons. Results Our data show that repeated administration of pioglitazone (10, 30 mg/kg) reduces high voluntary alcohol consumption in Wistar rats. Pre-treatment with the selective PPAR gamma antagonist GW9662 (5 mg/kg) completely prevented the effect of pioglitazone, demonstrating that its action is specifically mediated by activation of PPAR gamma. In line with this result, repeated administration of pioglitazone (30 mg/kg) attenuated binge alcohol consumption in PPAR gamma((+/+)) mice. Whereas in PPAR gamma((-/-)) mice, which exhibit reduced alcohol consumption, pioglitazone had no effect. Of note, PPAR gamma((-/-)) mice exhibited lower patterns of alcohol drinking without showing difference in sucrose (control) intake. Interestingly, PPAR gamma((-/-)) mice displayed a higher sensitivity to the sedative and ataxic effect of alcohol compared with their wild-type counterpart. Conclusions Collectively, these data suggest that PPAR gamma agonists, and specifically pioglitazone, could be potential therapeutics for the treatment of binge alcohol drinking.
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| 2. |
- Domi, Esi, et al.
(författare)
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Nicotine increases alcohol self-administration in male rats via a mu-opioid mechanism within the mesolimbic pathway
- 2020
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Ingår i: British Journal of Pharmacology. - : WILEY. - 0007-1188 .- 1476-5381. ; 177:19, s. 4516-4531
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Tidskriftsartikel (refereegranskat)abstract
- Background and Purpose: Alcohol and nicotine use disorders are commonly comorbid. Both alcohol and nicotine can activate opioid systems in reward-related brain regions, leading to adaptive changes in opioid signalling upon chronic exposure. The potential role of these adaptations for comorbidity is presently unknown. Here, we examined the contribution of mu and kappa-opioid receptors to nicotine-induced escalation of alcohol self-administration in rats. Experimental Approach: Chronic nicotine was tested on alcohol self-administration and motivation to obtain alcohol. We then tested the effect of the kappa antagonist CERC-501 and the preferential mu receptor antagonist naltrexone on basal and nicotine-escalated alcohol self-administration. To probe mu or kappa receptor adaptations, receptor binding and G-protein coupling assays were performed in reward-related brain regions. Finally, dopaminergic activity in response to alcohol was examined, using phosphorylation of DARPP-32 in nucleus accumbens as a biomarker. Key Results: Nicotine robustly induced escalation of alcohol self-administration and motivation to obtain alcohol. This was blocked by naltrexone but not by CERC-501. Escalation of alcohol self-administration was associated with decreased DAMGO-stimulated mu receptor signalling in the ventral tegmental area (VTA) and decreased pDARPP-32 in the nucleus accumbens shell in response to alcohol. Conclusions and Implications: Collectively, these results suggest that nicotine contributes to escalate alcohol self-administration through a dysregulation of mu receptor activity in the VTA. These data imply that targeting mu rather than kappa receptors may be the preferred pharmacotherapeutic approach for the treatment of alcohol use disorder when nicotine use contributes to alcohol consumption.
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