title: [Effects of chronic administration of alcohol on neural mechanisms of arterial blood pressure regulation].
abstract: OBJECTIVE
  This study evaluated the effect of alcohol and its withdrawal on arterial baroreflex (BR) and cardiopulmonary reflex (CPR).
  
  
  METHODS
  Male Wistar rats (150-250g) distributed in three groups (10-19 animals in each): ETOH 0%, ETOH 5% and ETOH 20%, received alcohol solution at the end of the day and at night over the week, and all day and night at the weekends for a 90 day period. The BR function was assessed analyzing the bradycardic response to phenylephrine-induced vasoconstriction and tachycardic response to sodium nitroprusside-induced vasodilatation. The CPR was evaluated through the simultaneous bradycardic and hypotensive responses to 5-hydroxytryptamine (5-HT). The tests were performed in conscious animals in conditions of alcohol intake or 48h alcohol withdrawal.
  
  
  RESULTS
  The nonwithdrawn animals of ETOH 5% group showed significative decrease of mean arterial pressure compared to ETOH 0% and an increase of heart rate compared to ETOH 0% and 20% groups. The sensitivity (gain) of baroreceptor reflex was significantly attenuated in ETOH 5% withdrawn animals and in ETOH 5% and 20% animals nonwithdrawn. This was mainly due to the reduction of range of the baroreflex and changes in the bradycardia and tachycardia plateau. The nonwithdrawn ETOH 5% group showed a higher effect of 5-HT (around 50%) on the fall of diastolic arterial pressure.
  
  
  CONCLUSIONS
  These results suggest that alcohol intake produced significant alterations in the neural mechanisms of cardiovascular regulation that could result in a dysfunction of blood pressure regulation.
authors.affiliation: Centro Biomédico da Universidade Federal do Espirito Santo, Vitória.
authors.forename: M S
authors.initials: MS
authors.lastname: Macieira
authors.forename: E A
authors.initials: EA
authors.lastname: Silva
authors.forename: W G
authors.initials: WG
authors.lastname: Almeida
authors.forename: E M
authors.initials: EM
authors.lastname: Nakamura-Palacios
authors.forename: E C
authors.initials: EC
authors.lastname: Vasquez
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D017704:Baroreflex / Q000187:drug effects*; D001794:Blood Pressure / Q000187:drug effects*; D001919:Bradycardia / Q000139:chemically induced; D000431:Ethanol / Q000494:pharmacology*; D006339:Heart Rate / Q000187:drug effects*; D008168:Lung / Q000187:drug effects*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D013375:Substance Withdrawal Syndrome; D013610:Tachycardia / Q000139:chemically induced
chemical_list: D000431:Ethanol