title: N-acetylcysteine modulates angiogenesis and vasodilation in stomach such as DNA damage in blood of portal hypertensive rats.
abstract: OBJECTIVE
  To evaluate the antioxidant effect of N-acetylcysteine (NAC) on the stomach of rats with portal hypertension.
  
  
  METHODS
  Twenty-four male Wistar rats weighing ± 250 g were divided into four experimental groups (n = 6 each): Sham-operated (SO), SO + NAC, partial portal vein ligation (PPVL), and PPVL + NAC. Treatment with NAC in a dose of 10 mg/kg (i.p.) diluted in 0.6 mL of saline solution was administered daily for 7 d starting 8 d after the surgery. Animals from the PPVL and SO group received saline solution (0.6 mL) for the same period of time as the PPVL + NAC and SO + NAC group. On the 15(th) day the animals were anesthetized and we evaluated portal pressure by cannulating mesenteric artery. After, we removed the stomach for further analysis. We performed immunohistochemical analysis for endothelial nitric oxide synthase (eNOS), vascular endothelial growth factor (VEGF), and nitrotirosine (NTT) proteins in stomach. We also evaluated eNOS and VEGF by Western blot analysis and assessed DNA damage in blood samples by the comet assay.
  
  
  RESULTS
  The portal hypertension group exhibited increases in portal pressure when compared to SO group (29.8 ± 1.8 vs 12.0 ± 0.3 mmHg) (P < 0.001). The same was observed when we compared the eNOS (56.8 ± 3.7 vs 13.46 ± 2.8 pixels) (P < 0.001), VEGF (34.9 ± 4.7 vs 17.46 ± 2.6 pixels) (P < 0.05), and NTT (39.01 ± 4.0 vs 12.77 ± 2.3 pixels) (P < 0.05) expression by immunohistochemistry of the PPVL animals with the SO group. The expression of eNOS (0.39 ± 0.03 vs 0.25 ± 0.03 a.μ) (P < 0.01) and VEGF (0.38 ± 0.04 vs 0.26 ± 0.04 a.μ) (P < 0.01) were also evaluated by Western blot analysis, and we observed an increase of both proteins on PPVL animals. We also evaluated the DNA damage by comet assay, and observed an increase on damage index and damage frequency on those animals. NAC decreased portal pressure values in PPVL + NAC animals (16.46 ± 2 vs 29.8 ± 1.8 mmHg) (P < 0.001) when compared to PPVL. The expression of eNOS (14.60 ± 4.1 vs 56.8 ± 3.7 pixels) (P < 0.001), VEGF (19.53 ± 3.2 vs 34.9 ± 4.7 pixels) (P < 0.05) and NTT (21.84 ± 0.7 vs 39.01 ± 4.0 pixels) (P < 0.05) evaluated by immunohistochemistry were also reduced in PPVL + NAC animals. Also, when evaluated by Western blot eNOS expression (0.32 ± 0.03 vs 0.39 ± 0.03 a.μ) (P < 0.05) and VEGF expression (0.31 ± 0.09 vs 0.38 ± 0.04 a.μ) (P < 0.01). Furthermore, NAC modulated DNA damage in PPVL + NAC animals.
  
  
  CONCLUSIONS
  In view of these results, we believe NAC is able to protect the stomach from the alterations induced by the PPVL procedure.
authors.affiliation: Francielli Licks, Renata Minuzzo Hartmann, Elizângela Schemitt, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS 90040-060, Brazil.
authors.forename: Francielli
authors.initials: F
authors.lastname: Licks
authors.affiliation: Francielli Licks, Renata Minuzzo Hartmann, Elizângela Schemitt, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS 90040-060, Brazil.
authors.forename: Renata Minuzzo
authors.initials: RM
authors.lastname: Hartmann
authors.affiliation: Francielli Licks, Renata Minuzzo Hartmann, Elizângela Schemitt, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS 90040-060, Brazil.
authors.forename: Camila
authors.initials: C
authors.lastname: Marques
authors.affiliation: Francielli Licks, Renata Minuzzo Hartmann, Elizângela Schemitt, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS 90040-060, Brazil.
authors.forename: Elizângela
authors.initials: E
authors.lastname: Schemitt
authors.affiliation: Francielli Licks, Renata Minuzzo Hartmann, Elizângela Schemitt, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS 90040-060, Brazil.
authors.forename: Josieli Raskopf
authors.initials: JR
authors.lastname: Colares
authors.affiliation: Francielli Licks, Renata Minuzzo Hartmann, Elizângela Schemitt, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS 90040-060, Brazil.
authors.forename: Mariana do Couto
authors.initials: Mdo C
authors.lastname: Soares
authors.affiliation: Francielli Licks, Renata Minuzzo Hartmann, Elizângela Schemitt, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS 90040-060, Brazil.
authors.forename: Juliana
authors.initials: J
authors.lastname: Reys
authors.affiliation: Francielli Licks, Renata Minuzzo Hartmann, Elizângela Schemitt, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS 90040-060, Brazil.
authors.forename: Camila
authors.initials: C
authors.lastname: Fisher
authors.affiliation: Francielli Licks, Renata Minuzzo Hartmann, Elizângela Schemitt, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS 90040-060, Brazil.
authors.forename: Juliana
authors.initials: J
authors.lastname: da Silva
authors.affiliation: Francielli Licks, Renata Minuzzo Hartmann, Elizângela Schemitt, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS 90040-060, Brazil.
authors.forename: Norma Possa
authors.initials: NP
authors.lastname: Marroni
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology*; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D015153:Blotting, Western; D020552:Comet Assay; D004249:DNA Damage / Q000187:drug effects*; D004195:Disease Models, Animal; D005753:Gastric Mucosa / Q000378:metabolism; D006975:Hypertension, Portal / Q000097:blood / Q000188:drug therapy* / Q000235:genetics / Q000503:physiopathology; D007150:Immunohistochemistry; D008297:Male; D009389:Neovascularization, Pathologic; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism; D017082:Portal Pressure / Q000187:drug effects; D017208:Rats, Wistar; D013270:Stomach / Q000098:blood supply* / Q000187:drug effects*; D014443:Tyrosine / Q000031:analogs & derivatives / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism; D014664:Vasodilation / Q000187:drug effects*
chemical_list: D000975:Antioxidants; D042461:Vascular Endothelial Growth Factor A; C467498:vascular endothelial growth factor A, rat; C002744:3-nitrotyrosine; D014443:Tyrosine; D052250:Nitric Oxide Synthase Type III; C496316:Nos3 protein, rat; D000111:Acetylcysteine
keywords: Antioxidant; Gastropathy; N-Acetylcysteine; Oxidative stress; Portal hypertension