Oxidative stress is not associated with vascular dysfunction in a model of alloxan-induced diabetic rats.
OBJECTIVE
To verify if an experimental model of alloxan-diabetic rats promotes oxidative stress, reduces nitric oxide bioavailability and causes vascular dysfunction, and to evaluate the effect of N-acetylcysteine (NAC) on these parameters.


METHODS
Alloxan-diabetic rats were treated or not with NAC for four weeks. Plasmatic levels of malondialdehyde (MDA) and nitrite/nitrate (NOx), the endothelial and inducible nitric oxide synthase (eNOS and iNOS) immunostaining and the vascular reactivity of aorta were compared among diabetic (D), treated diabetic (TD) and control (C) rats.


RESULTS
MDA levels increased in D and TD. NOx levels did not differ among groups. Endothelial eNOS immunostaining reduced and adventitial iNOS increased in D and TD. The responsiveness of rings to acetylcholine, sodium nitroprusside, and phenylephrine did not differ among groups.


CONCLUSIONS
NAC had no effect on the evaluated parameters and this experimental model did not promote vascular dysfunction despite the development of oxidative stress.
Capellini
Verena Kise
VK
Departamento de Cirurgia e Anatomia, Universidade de São Paulo, Ribeirão Preto, SP, Brazil.
Baldo
Caroline Floreoto
CF
Celotto
Andréa Carla
AC
Batalhão
Marcelo Eduardo
ME
Cárnio
Evelin Capellari
EC
Rodrigues
Alfredo José
AJ
Evora
Paulo Roberto Barbosa
PR
D000111:Acetylcysteine / Q000494:pharmacology*; D000496:Alloxan; D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects / Q000503:physiopathology; D003921:Diabetes Mellitus, Experimental / Q000188:drug therapy / Q000503:physiopathology*; D004195:Disease Models, Animal; D004730:Endothelium, Vascular / Q000502:physiology*; D016166:Free Radical Scavengers / Q000494:pharmacology*; D008297:Male; D008315:Malondialdehyde / Q000097:blood; D009569:Nitric Oxide / Q000502:physiology*; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III / Q000097:blood; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors
D016166:Free Radical Scavengers; D009569:Nitric Oxide; D008315:Malondialdehyde; D000496:Alloxan; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; D000111:Acetylcysteine