title: Aluminum exposure for one hour decreases vascular reactivity in conductance and resistance arteries in rats.
abstract: Aluminum (Al) is an important environmental contaminant; however, there are not enough evidences of Al-induced cardiovascular dysfunction. We investigated the effects of acute exposure to aluminum chloride (AlCl3) on blood pressure, vascular reactivity and oxidative stress.
  
  
  
  Male Wistar rats were divided into two groups: Untreated: vehicle (ultrapure water, ip) and AlCl3: single dose of AlCl3(100mg/kg,ip). Concentration-response curves to phenylephrine in the absence and presence of endothelium, the nitric oxide synthase inhibitor l-NAME, the potassium channel blocker tetraethylammonium, and the NADPH oxidase inhibitor apocynin were performed in segments from aortic and mesenteric resistance arteries. NO released was assessed in aorta and reactive oxygen species (ROS), malondialdehyde, non-protein thiol levels, antioxidant capacity and enzymatic antioxidant activities were investigated in plasma, aorta and/or mesenteric arteries. After one hour of AlCl3exposure serum Al levels attained 147.7±25.0μg/L. Al treatment: 1) did not affect blood pressure, heart rate and vasodilator responses induced by acetylcholine or sodium nitroprusside; 2) decreased phenylephrine-induced vasoconstrictor responses; 3) increased endothelial modulation of contractile responses, NO release and vascular ROS production from NADPH oxidase; 4) increased plasmatic, aortic and mesenteric malondialdehyde and ROS production, and 5) decreased antioxidant capacity and affected the antioxidant biomarkers non-protein thiol levels, glutathione peroxidase, glutathione-S-transferase, superoxide dismutase and catalase enzymatic activities.
  
  
  
  AlCl3-acute exposure reduces vascular reactivity. This effect is associated with increased NO production, probably acting on K+channels, which seems to occur as a compensatory mechanism against Al-induced oxidative stress. Our results suggest that Al exerts toxic effects to the vascular system.
authors.affiliation: Postgraduate Program in Biochemistry, Universidade Federal do Pampa, Uruguaiana, Rio Grande do Sul, Brazil.
authors.forename: Patrícia Medeiros
authors.initials: PM
authors.lastname: Schmidt
authors.affiliation: Postgraduate Program in Biochemistry, Universidade Federal do Pampa, Uruguaiana, Rio Grande do Sul, Brazil.
authors.forename: Alyne Goulart
authors.initials: AG
authors.lastname: Escobar
authors.affiliation: Postgraduate Program in Biochemistry, Universidade Federal do Pampa, Uruguaiana, Rio Grande do Sul, Brazil.
authors.forename: João Guilherme Dini
authors.initials: JG
authors.lastname: Torres
authors.affiliation: Postgraduate Program in Biochemistry, Universidade Federal do Pampa, Uruguaiana, Rio Grande do Sul, Brazil.
authors.forename: Caroline Silveira
authors.initials: CS
authors.lastname: Martinez
authors.affiliation: Postgraduate Program in Biochemistry, Universidade Federal do Pampa, Uruguaiana, Rio Grande do Sul, Brazil.
authors.forename: Danize Aparecida
authors.initials: DA
authors.lastname: Rizzetti
authors.affiliation: Postgraduate Program in Biochemistry, Universidade Federal do Pampa, Uruguaiana, Rio Grande do Sul, Brazil.
authors.forename: Simone Noremberg
authors.initials: SN
authors.lastname: Kunz
authors.affiliation: Department of Physiological Sciences, Universidade Federal do Espírito Santo, Espirito Santo, Brazil.
authors.forename: Dalton Valentim
authors.initials: DV
authors.lastname: Vassallo
authors.affiliation: Department of Basic Health Sciences, Universidad Rey Juan Carlos, Alcorcón, Spain.
authors.forename: María Jesús
authors.initials: MJ
authors.lastname: Alonso
authors.affiliation: Postgraduate Program in Biochemistry, Universidade Federal do Pampa, Uruguaiana, Rio Grande do Sul, Brazil.
authors.forename: Franck Maciel
authors.initials: FM
authors.lastname: Peçanha
authors.affiliation: Postgraduate Program in Biochemistry, Universidade Federal do Pampa, Uruguaiana, Rio Grande do Sul, Brazil. Electronic address: giuliawp@gmail.com.
authors.forename: Giulia Alessandra
authors.initials: GA
authors.lastname: Wiggers
mesh_terms: D000535:Aluminum / Q000633:toxicity*; D000818:Animals; D001158:Arteries / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism; D014655:Vascular Resistance
chemical_list: D017382:Reactive Oxygen Species; D000535:Aluminum
keywords: Acute exposure; Aluminum; Oxidative stress; Vascular reactivity