Premium
BAROREFLEX IMPAIRMENT IS CORRELATED WITH HIGH SUPEROXIDE DISMUTASE ACTIVITY IN METHIONINE‐TREATED RATS
Author(s) -
Mendes Roberta Hack,
Candido Georgia Orsi,
Mostarda Cristiano,
De la Fuente Raquel Nitrosi,
Jorge Luciana,
Silva Ivana C.M.,
BellóKlein Adriane,
Rigatto Katya,
Irigoyen Maria Claúdia Costa
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.737.4
Subject(s) - baroreflex , superoxide dismutase , homocysteine , hyperhomocysteinemia , chemistry , medicine , methionine , endocrinology , superoxide , blood pressure , heart rate , oxidative stress , biochemistry , amino acid , enzyme
Homocysteine (Hcy) is a suphur amino acid in methionine‐cysteine metabolism. Hyperhomocysteinemia is an independent risk factor for atherosclerosis. Purpose:To evaluate the effect of methionine treatment (ME) on systolic arterial pressure (SAP), heart rate (HR), baroreflex sensitivity (BRS) and superoxide dismutase (SOD) activity. Methods:Male wistar rats (n=5/group) were treated by gavage for 9 weeks (water=CO or ME=0,1g/kg in water). After treatment, rats were cannulated for cardiovascular measurements. BRS was evaluated by bradycardic (BR) and tachycardic responses (TR) to vasoactive drugs. Rats were killed and blood samples were collected, prepared and stored at −80ºC for SOD activity measurements. Results: Our results showed that ME increased SAP (117±8 vs 136±9 mmHg) and there was no difference in HR between groups (CO=324±13; M=337±11bpm). TR and BR in ME were decreased (2.4±0.4 vs 1.4±0.6; 1.9±0.5 vs 1.3±0.2 bpm/mmHg, respectively). SOD activity was higher in ME (14.8±1.8 vs 13±1.9 USOD/mg protein) and it was negatively correlated with BRS for both, TR (r=−0.8) and BR (r=−0.7). Conclusion: These data suggest that ME treatment increased SOD activity and induced a decrease on BRS, leading to an impairement on blood pressure control. Therefore, superoxide anion may participate in the baroreflex impairment.