Sex differences in the blood antioxidant defense system in juvenile rats with various genetic predispositions to hypertension.
This study investigated the contribution of blood oxidative stress (OS) to the development of hypertension, as well as sex differences in the antioxidant defense system (ADS) in genetic models of hypertension. Nine-week-old normotensive Wistar-Kyoto (WKY) rats, borderline hypertensive rats (BHR) and spontaneously hypertensive rats (SHR) of both sexes were used. Systolic blood pressure (SBP) was determined by tail-cuff plethysmography, the trolox equivalent antioxidant capacity (TEAC) and the concentration of lipid peroxides (LP) were determined in plasma. The activity of the antioxidant enzymes Cu/Zn-superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) was determined in erythrocytes. SBP was significantly elevated in BHR and SHR in both sexes. BHR and SHR males had a higher SBP than the respective females. Sex-dependent differences in the ADS were found only in SHR, in which TEAC, SOD and CAT were significantly higher in males than in females. No differences in TEAC, SOD, CAT and GPx were observed between BHR (males and females) and WKY controls. LP levels were similar in all the groups investigated. Significant positive correlations were observed between SBP and both SOD and CAT. TEAC correlated positively with SOD and LP. As no signs of oxidative damage to lipids were found in young BHR and SHR of either sex, OS in the blood does not seem to be causatively related to the development of hypertension in these rats. However, despite activated antioxidant defenses, the positive correlation between plasma TEAC and LP suggests that oxidative damage is progressing slowly and therefore it seems to be a consequence rather than the cause of hypertension.
Institute of Medical Chemistry, Biochemistry and Clinical Biochemistry, Faculty of Medicine, Comenius University Bratislava, Slovak Republic.
Martina
M
Horvathova
Institute of Medical Chemistry, Biochemistry and Clinical Biochemistry, Faculty of Medicine, Comenius University Bratislava, Slovak Republic.
Ingrid
I
Zitnanova
Institute of Medical Chemistry, Biochemistry and Clinical Biochemistry, Faculty of Medicine, Comenius University Bratislava, Slovak Republic.
Zuzana
Z
Kralovicova
Institute of Normal and Pathological Physiology, Slovak Academy of Sciences, Centre of Excellence for Examination of Regulatory Role of Nitric Oxide in Civilization Diseases, Bratislava, Slovak Republic.
Peter
P
Balis
Institute of Normal and Pathological Physiology, Slovak Academy of Sciences, Centre of Excellence for Examination of Regulatory Role of Nitric Oxide in Civilization Diseases, Bratislava, Slovak Republic.
Angelika
A
Puzserova
Institute of Medical Chemistry, Biochemistry and Clinical Biochemistry, Faculty of Medicine, Comenius University Bratislava, Slovak Republic.
Jana
J
Muchova
Institute of Normal and Pathological Physiology, Slovak Academy of Sciences, Centre of Excellence for Examination of Regulatory Role of Nitric Oxide in Civilization Diseases, Bratislava, Slovak Republic.
Michal
M
Kluknavsky
Institute of Medical Chemistry, Biochemistry and Clinical Biochemistry, Faculty of Medicine, Comenius University Bratislava, Slovak Republic.
Zdenka
Z
Durackova
Institute of Normal and Pathological Physiology, Slovak Academy of Sciences, Centre of Excellence for Examination of Regulatory Role of Nitric Oxide in Civilization Diseases, Bratislava, Slovak Republic.
Iveta
I
Bernatova
D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D001794:Blood Pressure; D002374:Catalase / Q000378:metabolism; D005260:Female; D020022:Genetic Predisposition to Disease; D005979:Glutathione Peroxidase / Q000235:genetics; D006339:Heart Rate / Q000235:genetics; D006973:Hypertension / Q000235:genetics* / Q000378:metabolism* / Q000503:physiopathology; D015227:Lipid Peroxidation / Q000187:drug effects; D008297:Male; D018384:Oxidative Stress / Q000235:genetics; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D012727:Sex Characteristics; D013482:Superoxide Dismutase / Q000378:metabolism
D000975:Antioxidants; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase