title: Stress alone or associated with ethanol induces prostanoid release in rat aorta via alpha2-Adrenoceptor.
abstract: BACKGROUND
  Stress and ethanol are both, independently, important cardiovascular risk factors.
  
  
  OBJECTIVE
  To evaluate the cardiovascular risk of ethanol consumption and stress exposure, isolated and in association, in male adult rats.
  
  
  METHODS
  Rats were separated into 4 groups: Control, ethanol (20% in drinking water for 6 weeks), stress (immobilization 1h day/5 days a week for 6 weeks) and stress/ethanol. Concentration-responses curves to noradrenaline - in the absence and presence of yohimbine, L-NAME or indomethacin - or to phenylephrine were determined in thoracic aortas with and without endothelium. EC50 and maximum response (n=8-12) were compared using two-way ANOVA/Bonferroni method.
  
  
  RESULTS
  Either stress or stress in association with ethanol consumption increased the noradrenaline maximum responses in intact aortas. This hyper-reactivity was eliminated by endothelium removal or by the presence of either indomethacin or yohimbine, but was not altered by the presence of L-NAME. Meanwhile, ethanol consumption did not alter the reactivity to noradrenaline. The phenylephrine responses in aortas both with and without endothelium also remained unaffected regardless of protocol.
  
  
  CONCLUSIONS
  Chronic stress increased rat aortic responses to noradrenaline. This effect is dependent upon the vascular endothelium and involves the release of vasoconstrictor prostanoids via stimulation of endothelial alpha-2 adrenoceptors. Moreover, chronic ethanol consumption appeared to neither influence noradrenaline responses in rat thoracic aorta, nor did it modify the increase of such responses observed as a consequence of stress exposure.
authors.affiliation: Departamento de Farmacologia, Instituto de Biociências, Universidade Estadual Paulista, São Paulo, SP, Brasil.
authors.forename: Rafaela de Fátima Ferreira
authors.initials: Rde F
authors.lastname: Baptista
authors.affiliation: Laboratório de Farmacologia, Faculdade de Medicina de Marília, SP, Brasil.
authors.forename: Elane de Fátima
authors.initials: Ede F
authors.lastname: Taipeiro
authors.affiliation: Departamento de Análise Clínica - Toxicológica e Ciência de Alimentos, Faculdade de Ciências Farmacêuticas, USP, São Paulo, SP, Brasil.
authors.forename: Regina Helena Costa
authors.initials: RH
authors.lastname: Queiroz
authors.affiliation: Departamento de Farmacologia, Instituto de Biociências, Universidade Estadual Paulista, São Paulo, SP, Brasil.
authors.forename: Agnaldo Bruno
authors.initials: AB
authors.lastname: Chies
authors.affiliation: Departamento de Farmacologia, Instituto de Biociências, Universidade Estadual Paulista, São Paulo, SP, Brasil.
authors.forename: Sandra
authors.initials: S
authors.lastname: Cordellini
mesh_terms: D000428:Alcohol Drinking / Q000009:adverse effects; D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects* / Q000378:metabolism; D002318:Cardiovascular Diseases / Q000209:etiology; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism; D000431:Ethanol / Q000009:adverse effects* / Q000097:blood; D008297:Male; D009566:Nitrates / Q000097:blood; D009573:Nitrites / Q000097:blood; D009638:Norepinephrine / Q000032:analysis / Q000378:metabolism*; D011453:Prostaglandins / Q000378:metabolism*; D017208:Rats, Wistar; D018341:Receptors, Adrenergic, alpha-2 / Q000187:drug effects*; D012016:Reference Values; D012307:Risk Factors; D013312:Stress, Physiological / Q000187:drug effects*; D013997:Time Factors
chemical_list: D009566:Nitrates; D009573:Nitrites; D011453:Prostaglandins; D018341:Receptors, Adrenergic, alpha-2; D000431:Ethanol; D009638:Norepinephrine