Influence of ovariectomy on cardiac oxidative stress in a renovascular hypertension model.
The aim of this study was to evaluate the potential influence of endogenous ovarian hormones on cardiac oxidative stress in renovascular hypertension. Female Wistar rats (N = 10 per group) were divided among 4 groups: (i) normotensive control; (ii) hypertensive control; (iii) normotensive ovariectomized; and (iv) hypertensive ovariectomized rats. To induce hypertension, 2-kidney 1-clip (2K1C) Goldblatt's method was followed. Blood pressure (BP) was enhanced (25%) in 2K1C and it was not further altered in hypertensive ovariectomized animals. Lipid peroxidation (measured by thiobarbituric acid reactive substances; TBARS) increased in heart homogenates after ovariectomy (253%) and was additionally augmented when associated with hypertension (by 28%). Superoxide dismutase and catalase activities were similar in both hypertensive groups. Hypertension enhanced glutathione peroxidase activity (75%), but the association with ovariectomy prevented this change. Total radical trapping antioxidant potential (TRAP) decreased in hypertensive rats (34%) and was recovered when associated with ovariectomy. However, this adaptation seems not to be sufficient to avoid the increased oxidative damage in ovariectomized hypertensive animals. These results suggest a protective role for physiological ovarian hormones in the cardiac oxidative stress induced by 2K1C hypertension.
Cardiovascular Physiology Laboratory, Federal University of Rio Grande do Sul, CEP, Porto Alegre, Brazil.
Jaqueline
J
Barp
Carmem Luiza
CL
Sartório
Cristina
C
Campos
Susana Francisca
SF
Llesuy
Alex Sander
AS
Araujo
Adriane
A
Belló-Klein
D000818:Animals; D001794:Blood Pressure; D002374:Catalase / Q000378:metabolism; D004195:Disease Models, Animal; D004967:Estrogens / Q000378:metabolism; D005260:Female; D005979:Glutathione Peroxidase / Q000378:metabolism; D006978:Hypertension, Renovascular / Q000378:metabolism*; D015227:Lipid Peroxidation; D009206:Myocardium / Q000201:enzymology / Q000378:metabolism*; D010052:Ovariectomy; D018384:Oxidative Stress; D051381:Rats; D017208:Rats, Wistar; D013482:Superoxide Dismutase / Q000378:metabolism; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
D004967:Estrogens; D017392:Thiobarbituric Acid Reactive Substances; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase