Browsing by Author "Opacic, M. (8443925800)"

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=22;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. © 2006 Nature Publishing Group All rights reserved.

Objectives. To perform a systematic functional investigation of different glutathione S-transferase (GST) classes, including GST class Theta (GSTT) member GSTT1-1, in transitional cell carcinoma (TCC) and the surrounding normal uroepithelium of the same individuals. Recently, it was suggested that GSTT1-1 might be an important risk modulator for TCC. Methods. Tumor samples and surrounding normal uroepithelium were obtained from 24 patients with TCC of urinary bladder. The following substrates with differential specificities were used: 1-chloro-2,4-dinitrobenzene for overall GST activity; 7-chloro-4- nitrobenzo-2-oxa-1,3-diazole for GST Alpha; 1,2-dichloro-4-nitro-benzene for GST Mu; 4-vinylpyridine for GST Pi 1-1(GSTP1-1); and 1,2-epoxy-3-(p-nitrophenoxy) propane for GSTT1-1. Results. GSTP1-1 and GSTT1-1 activities were demonstrated in all uroepithelial and TCC samples, and GST Mu activity was detectable in 11 of 24 patients. In the tumor specimens, significant upregulation of all expressed GST subtypes was observed. The mean GSTP1-1 and GSTT1-1 level in TCC was increased 2-fold and 3.6-fold, respectively, compared with the mean level in the normal uroepithelium (P <0.001). Tumor GSTT1-1 activities correlated statistically significantly with the tumor stage (P <0.05). Conclusions. In tumors and adjacent normal uroepithelium of patients with TCC, three major cytosolic GST classes, Mu, Pi, and Theta, were expressed. Although the GST isoenzyme pattern in TCC was similar to that of the corresponding normal uroepithelium, during cancer progression a clear tendency toward an increase in all the GST subtypes expressed was noted. For the first time, distinct GSTT1-1 activity levels were demonstrated in human uroepithelium, as well as its pronounced upregulation in TCC. © 2005 Elsevier Inc.