Catalase inhibition in the Arcuate nucleus blocks ethanol effects on the locomotor activity of rats.
Previous studies have demonstrated that there is a bidirectional modulation of ethanol-induced locomotion produced by drugs that regulate brain catalase activity. In the present study we have assessed the effect in rats of intraperitoneal, intraventricular or intracraneal administration of the catalase inhibitor sodium azide in the locomotor changes observed after ethanol (1 g/kg) administration. Our results show that sodium azide prevents the effects of ethanol in rats locomotion not only when sodium azide was systemically administered but also when it was intraventricularly injected, then confirming that the interaction between catalase and ethanol takes place in Central Nervous System (CNS). Even more interestingly, the same results were observed when sodium azide administration was restricted to the hypothalamic Arcuate nucleus (ARC), a brain region which has one of the highest levels of expression of catalase. Therefore, the results of the present study not only confirm a role for brain catalase in the mediation of ethanol-induced locomotor changes in rodents but also point to the ARC as a major neuroanatomical location for this interaction. These results are in agreement with our reports showing that ethanol-induced locomotor changes are clearly dependent of the ARC integrity and, especially of the POMc-synthesising neurons of this nucleus. According to these data we propose a model in which ethanol oxidation via catalase could produce acetaldehyde into the ARC and to promote a release of beta-endorphins that would activate opioid receptors to produce locomotion and other ethanol-induced neurobehavioural changes.
Sanchis-Segura
Carles
C
Area de Psicobiologia, Universitat Jaume I, Campus de Riu Sec, Apartat. 8029 AP, Castelló 12071, Spain.
Correa
Mercé
M
Miquel
Marta
M
Aragon
Carlos M G
CM
D000704:Analysis of Variance; D000818:Animals; D001111:Arcuate Nucleus of Hypothalamus / Q000187:drug effects*; D001522:Behavior, Animal; D002374:Catalase / Q000037:antagonists & inhibitors*; D002492:Central Nervous System Depressants; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004791:Enzyme Inhibitors / Q000494:pharmacology; D000431:Ethanol / Q000494:pharmacology*; D008954:Models, Biological; D009043:Motor Activity / Q000187:drug effects*; D009433:Neural Inhibition / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D019810:Sodium Azide / Q000494:pharmacology
D002492:Central Nervous System Depressants; D004791:Enzyme Inhibitors; D000431:Ethanol; D019810:Sodium Azide; D002374:Catalase