title: Effects of exercise training on stress-induced vascular reactivity alterations: role of nitric oxide and prostanoids.
abstract: BACKGROUND
  Physical exercise may modify biologic stress responses.
  
  
  OBJECTIVE
  To investigate the impact of exercise training on vascular alterations induced by acute stress, focusing on nitric oxide and cyclooxygenase pathways.
  
  
  METHODS
  Wistar rats were separated into: sedentary, trained (60-min swimming, 5 days/week during 8 weeks, carrying a 5% body-weight load), stressed (2 h-immobilization), and trained/stressed. Response curves for noradrenaline, in the absence and presence of L-NAME or indomethacin, were obtained in intact and denuded aortas (n = 7-10).
  
  
  RESULTS
  None of the procedures altered the denuded aorta reactivity. Intact aortas from stressed, trained, and trained/stressed rats showed similar reduction in noradrenaline maximal responses (sedentary 3.54 ± 0.15, stressed 2.80 ± 0.10*, trained 2.82 ± 0.11*, trained/stressed 2.97 ± 0.21*, *P < 0.05 relate to sedentary). Endothelium removal and L-NAME abolished this hyporeactivity in all experimental groups, except in trained/stressed rats that showed a partial aorta reactivity recovery in L-NAME presence (L-NAME: sedentary 5.23 ± 0,26#, stressed 5.55 ± 0.38#, trained 5.28 ± 0.30#, trained/stressed 4.42 ± 0.41, #P < 0.05 related to trained/stressed). Indomethacin determined a decrease in sensitivity (EC50) in intact aortas of trained rats without abolishing the aortal hyporeactivity in trained, stressed, and trained/stressed rats.
  
  
  CONCLUSIONS
  Exercise-induced vascular adaptive response involved an increase in endothelial vasodilator prostaglandins and nitric oxide. Stress-induced vascular adaptive response involved an increase in endothelial nitric oxide. Beside the involvement of the endothelial nitric oxide pathway, the vascular response of trained/stressed rats involved an additional mechanism yet to be elucidated. These findings advance on the understanding of the vascular processes after exercise and stress alone and in combination.
authors.affiliation: Departamento de Farmacologia, Instituto de Biociências, Universidade Estadual Paulista, Botucatu, SP, Brazil.
authors.forename: Thiago
authors.initials: T
authors.lastname: Bruder-Nascimento
authors.affiliation: Departamento de Proteção Vegetal, Faculdade de Ciências Agronômicas, UNESP, Botucatu, SP, Brazil.
authors.forename: Samuel T
authors.initials: ST
authors.lastname: Silva
authors.affiliation: Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas, SP, Brazil.
authors.forename: Patrícia A
authors.initials: PA
authors.lastname: Boer
authors.affiliation: Departamento de Farmacologia, Instituto de Biociências, Universidade Estadual Paulista, Botucatu, SP, Brazil.
authors.forename: Sandra
authors.initials: S
authors.lastname: Cordellini
mesh_terms: D000818:Animals; D001808:Blood Vessels / Q000502:physiology*; D008297:Male; D009569:Nitric Oxide / Q000502:physiology*; D010805:Physical Conditioning, Animal; D011453:Prostaglandins / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D013312:Stress, Physiological
chemical_list: D011453:Prostaglandins; D009569:Nitric Oxide