Ats had mild anemia, larger plasma urea and creatinine. Markers of oxidative tension have been improved in CKD: TBARS and 8-isoprostane excretion had been substantially higher, whereas H2O2 excretion tended to improve vs. CON rats. NOx excretion tended to lower in CKD vs. CON. In CKD rats, the expression of renin and VEGF-A had been reduced in comparison to Comparison of changes induced by Tempol, PEG-catalase and vehicle Hypertension in CKD Doesn’t Rely on ROS CON baseline N GFR FE Na FE K 4 MedChemExpress SPI 1005 672665 0.2860.12 26.0961.94 baseline N GFR FE Na FE K five 7846105 0.1560.04 30.4763.53 baseline N GFR FE Na FE K four 7416102.13 0.1760.04 30.6760.79 5236107 1 0.1660.05 26.7761.94 5106112 &&& 0.1260.04 28.6763.56 automobile 485660 $$ 0.2360.13 25.1160.73 PEG-catalase Tempol CKD baseline 6 302618 ### 1.0260.26 64.2264.61 ### baseline eight 354640 ### 0.4760.08 63.4265.41 ### baseline 4 303632 ## 1.2760.60 73.50 68.58 ## 240628 # 1.6060.92 73.4567.64 ## 273624 1527786 ## 0.7960.14 ### &&& 60.9664.98 ### car 262621 ## 1.9160.54 # $$ 62.4363.90 ### PEG-catalase Tempol P-value CKD-cat Tempol Interaction ,0.001 = 0.042,0.001 CKD = 0.003 = 0.066 = 0.665 PEG-catalase = 0.029 = 0.043 = 0.898 Interaction ,0.001 = 0.005,0.001 CKD ,0.001 = 0.026 = 0.501 car = 0.021 = 0.009 = 0.915 Interaction = 0.013 = 0.145 = 0.001 = 0.007 = 0.364 = 0.273 = 0.066 = 0.342 = 0.284 Mean 6 SEM, ANOVA RM, Tukey post-hoc test for comparison between groups ### P,0.001, ## P,0.01, #P,0.05 vs. CON; $$P,0.01 Tempol vs. baseline; &&& P,0.001 PEG-catalase vs. baseline; 1 P,0.05 car vs. baseline. doi:10.1371/journal.pone.0088596.t003 in MAP caused by PEG-catalase administration, the opposite was observed: MAP decreased slightly in CON 1662274 rats but was substantially lower in CKD rats when compared to change caused by vehicle infusion in the same condition. Modifications in RVR have been not significantly different. One-hour acute infusion of Tempol or PEG-catalase in terminal setting did not cause any changes in the renal expression of RAS and VEGF-A genes or in tyrosine hydroxylase staining in comparison to car infusion in both CON and CKD. down-regulation of renal catalase and glutathione peroxidase protein abundance and catalase activity. Effect of Tempol and PEG-catalase on MAP In CKD rat models chronic Tempol administration only ameliorated hypertension for 1014 days after nephrectomy. Our data suggests that in long-term experimental CKD, once hypertension is established, other mechanisms contribute to its maintenance. Because Tempol caused a marked reduce in MAP in CON but not in CKD rats, maintenance of hypertension in our model of CKD appears not to rely on superoxide. Although Tempol infusion reduces superoxide levels, it results in accumulation of H2O2 that might serve as an important hypertensive factor and has been reported to induce renal vasoconstriction. The lack of antihypertensive effects of Tempol might be explained by the need of a fully functional system of other antioxidant enzymes to drive the H2O2 generated from superoxide dismutation to CO2 and H2O. In contrast to Tempol, we found that acute administration of PEGcatalase did reduce MAP in CKD. However, MAP was not normalized to control levels in response to PEG-catalase, suggesting that H2O2 is not solely responsible for hypertension in MedChemExpress 307538-42-7 established CKD. Enhanced production of ROS can reduce the availability of vasodilators such as nitric oxide, which can lead to functional NO deficiency and thus contribute to maintenance of hypertensi.Ats had mild anemia, larger plasma urea and creatinine. Markers of oxidative anxiety had been enhanced in CKD: TBARS and 8-isoprostane excretion have been substantially larger, whereas H2O2 excretion tended to increase vs. CON rats. NOx excretion tended to decrease in CKD vs. CON. In CKD rats, the expression of renin and VEGF-A were reduced in comparison to Comparison of adjustments induced by Tempol, PEG-catalase and car Hypertension in CKD Doesn’t Rely on ROS CON baseline N GFR FE Na FE K 4 672665 0.2860.12 26.0961.94 baseline N GFR FE Na FE K 5 7846105 0.1560.04 30.4763.53 baseline N GFR FE Na FE K four 7416102.13 0.1760.04 30.6760.79 5236107 1 0.1660.05 26.7761.94 5106112 &&& 0.1260.04 28.6763.56 automobile 485660 $$ 0.2360.13 25.1160.73 PEG-catalase Tempol CKD baseline 6 302618 ### 1.0260.26 64.2264.61 ### baseline 8 354640 ### 0.4760.08 63.4265.41 ### baseline 4 303632 ## 1.2760.60 73.50 68.58 ## 240628 # 1.6060.92 73.4567.64 ## 273624 1527786 ## 0.7960.14 ### &&& 60.9664.98 ### automobile 262621 ## 1.9160.54 # $$ 62.4363.90 ### PEG-catalase Tempol P-value CKD-cat Tempol Interaction ,0.001 = 0.042,0.001 CKD = 0.003 = 0.066 = 0.665 PEG-catalase = 0.029 = 0.043 = 0.898 Interaction ,0.001 = 0.005,0.001 CKD ,0.001 = 0.026 = 0.501 car = 0.021 = 0.009 = 0.915 Interaction = 0.013 = 0.145 = 0.001 = 0.007 = 0.364 = 0.273 = 0.066 = 0.342 = 0.284 Mean 6 SEM, ANOVA RM, Tukey post-hoc test for comparison between groups ### P,0.001, ## P,0.01, #P,0.05 vs. CON; $$P,0.01 Tempol vs. baseline; &&& P,0.001 PEG-catalase vs. baseline; 1 P,0.05 car vs. baseline. doi:10.1371/journal.pone.0088596.t003 in MAP caused by PEG-catalase administration, the opposite was observed: MAP decreased slightly in CON 1662274 rats but was considerably decrease in CKD rats when compared to change caused by car infusion in the same condition. Changes in RVR were not substantially different. One-hour acute infusion of Tempol or PEG-catalase in terminal setting did not cause any modifications in the renal expression of RAS and VEGF-A genes or in tyrosine hydroxylase staining in comparison to automobile infusion in both CON and CKD. down-regulation of renal catalase and glutathione peroxidase protein abundance and catalase activity. Effect of Tempol and PEG-catalase on MAP In CKD rat models chronic Tempol administration only ameliorated hypertension for 1014 days after nephrectomy. Our data suggests that in long-term experimental CKD, once hypertension is established, other mechanisms contribute to its maintenance. Because Tempol caused a marked reduce in MAP in CON but not in CKD rats, maintenance of hypertension in our model of CKD appears not to depend on superoxide. Although Tempol infusion reduces superoxide levels, it results in accumulation of H2O2 that might serve as an important hypertensive factor and has been reported to induce renal vasoconstriction. The lack of antihypertensive effects of Tempol might be explained by the need of a fully functional system of other antioxidant enzymes to drive the H2O2 generated from superoxide dismutation to CO2 and H2O. In contrast to Tempol, we found that acute administration of PEGcatalase did lower MAP in CKD. However, MAP was not normalized to control levels in response to PEG-catalase, suggesting that H2O2 is not solely responsible for hypertension in established CKD. Enhanced production of ROS can lessen the availability of vasodilators such as nitric oxide, which can lead to functional NO deficiency and thus contribute to maintenance of hypertensi.