title: Protracted alcohol abstinence induces analgesia in rats: Possible relationships with BDNF and interleukin-10.
abstract: Exposure to ethanol alters the expression of brain-derived neurotrophic factor (BDNF) in central regions such as, the hippocampus, cortex and striatum. Moreover, chronic alcohol intake is known to induce selective neuronal damage associated with an increase in the inflammatory cascade, resulting in neuronal apoptosis and neurodegeneration. In the present study, we investigated the nociceptive response after 24h of protracted alcohol abstinence. Rats were submitted to a model of alcohol withdrawal syndrome and the nociceptive response was assessed by the tail-flick and the hot plate tests. In addition, we evaluated BDNF and interleukin-10 (IL-10) in the cerebral prefrontal cortex, brainstem and hippocampus of rats after protracted alcohol abstinence. Male adult Wistar rats were divided into three groups: non-treated group (control group), treated with water (water group), and alcohol (alcohol group). The water and alcohol administrations were done by oral gavage and were performed over three periods of five days of treatment with two intervals of two days between them. Alcohol (20%w/v) was given at 4g/kg of body weight. There was a significant effect of treatment in the tail-flick and hot plate latencies with greater latencies in alcohol-treated rats after 10days of abstinence. There was a significant increase in the prefrontal cortex BDNF levels in the alcohol group in relation to the water group, after 11days of alcohol abstinence. In addition, alcohol withdrawal induced a significant increase in the hippocampus, prefrontal cortex and brainstem IL-10 levels compared with control group. Thus, the present study demonstrates that protracted alcohol withdrawal produced an analgesic effect indexed via increased nociceptive threshold. We suggest that these effects could be related to the increased levels of BDNF and IL-10 observed in the central nervous system.
authors.affiliation: Graduate Program in Biological Sciences - Neuroscience, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre 90050-170, Brazil.
authors.forename: Rebeca Vargas Antunes
authors.initials: RV
authors.lastname: Schunck
authors.affiliation: Pain Pharmacology and Neuromodulation Laboratory: Animal Models, Department of Pharmacology, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre 90050-170, Brazil. Electronic address: iracitorres@gmail.com.
authors.forename: Iraci L S
authors.initials: IL
authors.lastname: Torres
authors.affiliation: Pain Pharmacology and Neuromodulation Laboratory: Animal Models, Department of Pharmacology, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre 90050-170, Brazil.
authors.forename: Gabriela
authors.initials: G
authors.lastname: Laste
authors.affiliation: Pain Pharmacology and Neuromodulation Laboratory: Animal Models, Department of Pharmacology, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre 90050-170, Brazil.
authors.forename: Andressa
authors.initials: A
authors.lastname: de Souza
authors.affiliation: Pain Pharmacology and Neuromodulation Laboratory: Animal Models, Department of Pharmacology, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre 90050-170, Brazil.
authors.forename: Isabel Cristina
authors.initials: IC
authors.lastname: Macedo
authors.affiliation: Graduate Program in Biological Sciences - Neuroscience, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre 90050-170, Brazil.
authors.forename: Marina Tuerlinckx Costa
authors.initials: MT
authors.lastname: Valle
authors.affiliation: Laboratory of Pharmacology and Toxicology of Natural Products, Department of Pharmacology, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre 90050-170, Brazil.
authors.forename: Janaína L O
authors.initials: JL
authors.lastname: Salomón
authors.affiliation: Pain Pharmacology and Neuromodulation Laboratory: Animal Models, Department of Pharmacology, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre 90050-170, Brazil.
authors.forename: Sonia
authors.initials: S
authors.lastname: Moreira
authors.affiliation: Pain Pharmacology and Neuromodulation Laboratory: Animal Models, Department of Pharmacology, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre 90050-170, Brazil.
authors.forename: Jonnsin
authors.initials: J
authors.lastname: Kuo
authors.affiliation: REQUIMTE, Toxicology Laboratory, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, Porto 4050-313, Portugal.
authors.forename: Marcelo Dutra
authors.initials: MD
authors.lastname: Arbo
authors.affiliation: Department Farmaco Sciences, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre 90050-170, Brazil.
authors.forename: Eliane
authors.initials: E
authors.lastname: Dallegrave
authors.affiliation: Graduate Program in Biological Sciences - Neuroscience, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre 90050-170, Brazil; Laboratory of Pharmacology and Toxicology of Natural Products, Department of Pharmacology, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre 90050-170, Brazil. Electronic address: mirnablufrgs@gmail.com.
authors.forename: Mirna Bainy
authors.initials: MB
authors.lastname: Leal
mesh_terms: D000698:Analgesia; D000818:Animals; D001923:Brain Chemistry / Q000187:drug effects; D019208:Brain-Derived Neurotrophic Factor / Q000378:metabolism*; D002492:Central Nervous System Depressants / Q000494:pharmacology*; D000431:Ethanol / Q000494:pharmacology*; D016753:Interleukin-10 / Q000378:metabolism*; D008297:Male; D010147:Pain Measurement / Q000187:drug effects; D017288:Pain Threshold / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D013375:Substance Withdrawal Syndrome / Q000523:psychology*
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D002492:Central Nervous System Depressants; D016753:Interleukin-10; D000431:Ethanol
keywords: Alcohol withdrawal; BDNF; Interleukin-10; Nociception