Byproducts of oxidative protein damage and antioxidant enzyme activities in plasma of patients with different degrees of essential hypertension.
Despite evidence that essential hypertension (EH) is a state of increased oxidative stress, the data on oxidative protein modifications is lacking. Besides, the role of extracellular antioxidant enzymes in EH has not been systematically studied. Study was performed in 45 subjects with EH and 25 normotensive controls. Patients were divided into three groups according to the 2003 ESH/ESC guidelines (grade 1-3). Plasma protein reactive carbonyl derivatives (RCD) and SH-groups (as byproducts of oxidative protein damage) as well as antioxidant enzyme activities superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase were studied spectrophotometrically and correlated with blood pressure (BP). RCD levels were increased in EH patients compared to controls and correlated significantly with both systolic blood pressure (SBP) (r = 0.495, P<0.01) and diastolic blood pressure (DBP) (r = 0.534, P<0.01). Plasma SH-groups content was significantly lower in all patients with EH, with no correlation with BP. SOD and catalase activity in patients with grade 1 EH were similar to that of controls. Patients with grade 2 and 3 of EH had lower SOD and catalase activity. However, significant correlation with SBP and DBP was observed for catalase only (r = -0.331; P<0.05 and r = -0.365; P<0.05, respectively). EH patients exhibited higher plasma GPX activity compared to those in controls, and it correlated with SBP (r = 0.328; P<0.05). The results presented show that increased oxidative protein damage is present in all grades of EH. In mild hypertension extracellular antioxidant enzyme activities are not decreased, suggesting they are probably not critical in early EH, but could be important in moderate to severe EH.
Simic
D V
DV
Institute for Cardiovascular Disease, Clinical Centre of Serbia, University of Belgrade, Serbia and Montenegro.
Mimic-Oka
J
J
Pljesa-Ercegovac
M
M
Savic-Radojevic
A
A
Opacic
M
M
Matic
D
D
Ivanovic
B
B
Simic
T
T
D000704:Analysis of Variance; D001794:Blood Pressure / Q000502:physiology*; D001798:Blood Proteins / Q000378:metabolism*; D016022:Case-Control Studies; D002374:Catalase / Q000097:blood; D005260:Female; D005979:Glutathione Peroxidase / Q000097:blood; D006801:Humans; D006973:Hypertension / Q000097:blood*; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress / Q000502:physiology*; D010659:Phenylhydrazines / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013438:Sulfhydryl Compounds / Q000097:blood; D013482:Superoxide Dismutase / Q000097:blood
D001798:Blood Proteins; D010659:Phenylhydrazines; D017382:Reactive Oxygen Species; D013438:Sulfhydryl Compounds; C004787:2,4-dinitrophenylhydrazine; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase