OBJECTIVE: Oxidative stress has been implicated in the pathogenesis of hypertension and its complications through alterations in nitric oxide (NO) metabolism. This study was designed to investigate whether a relationship exists between phagocytic nicotinamide adenine dinucleotide phosphate (NADPH) oxidase-dependent superoxide anion (*O2-) production and NO generation in patients with essential hypertension. METHODS: Superoxide production was assayed by chemiluminescence under baseline and stimulated conditions on mononuclear cells obtained from hypertensives (n=51) and normotensives (n=43). NO production was evaluated by determining serum NO metabolites, nitrate plus nitrite (NOx). RESULTS: Although there were no differences in baseline *O2- production between normotensives and hypertensives, the *O2- production in phorbol myristate acetate (PMA)-stimulated mononuclear cells was increased (P <0.05) in hypertensives compared with normotensives. The PMA-induced *O2- production was completely abolished by apocynin, a specific inhibitor of NADPH oxidase. Moreover, stimulation of *O2- production by angiotensin II and endothelin-1 was higher (P <0.05) in cells from hypertensives than in cells from normotensives. In addition, diminished (P <0.001) serum NOx was detected in hypertensives compared with normotensives. Interestingly, an inverse correlation (r=0.493, P <0.01) was found between *O2- production and NOx in hypertensives. CONCLUSIONS: Generation of *O2- mainly dependent on NADPH oxidase is abnormally enhanced in stimulated mononuclear cells from hypertensives. It is suggested that this alteration could be involved in the diminished NO production observed in these patients.
OBJECTIVE: Oxidative stress has been implicated in the pathogenesis of hypertension and its complications through alterations in nitric oxide (NO) metabolism. This study was designed to investigate whether a relationship exists between phagocytic nicotinamide adenine dinucleotide phosphate (NADPH) oxidase-dependent superoxide anion (*O2-) production and NO generation in patients with essential hypertension. METHODS:Superoxide production was assayed by chemiluminescence under baseline and stimulated conditions on mononuclear cells obtained from hypertensives (n=51) and normotensives (n=43). NO production was evaluated by determining serum NO metabolites, nitrate plus nitrite (NOx). RESULTS: Although there were no differences in baseline *O2- production between normotensives and hypertensives, the *O2- production in phorbol myristate acetate (PMA)-stimulated mononuclear cells was increased (P <0.05) in hypertensives compared with normotensives. The PMA-induced *O2- production was completely abolished by apocynin, a specific inhibitor of NADPH oxidase. Moreover, stimulation of *O2- production by angiotensin II and endothelin-1 was higher (P <0.05) in cells from hypertensives than in cells from normotensives. In addition, diminished (P <0.001) serum NOx was detected in hypertensives compared with normotensives. Interestingly, an inverse correlation (r=0.493, P <0.01) was found between *O2- production and NOx in hypertensives. CONCLUSIONS: Generation of *O2- mainly dependent on NADPH oxidase is abnormally enhanced in stimulated mononuclear cells from hypertensives. It is suggested that this alteration could be involved in the diminished NO production observed in these patients.
Authors: Neha Singh; Shrinidh Joshi; Lirong Guo; Matthew B Baker; Yan Li; Ronald K Castellano; Mohan K Raizada; Yagna P R Jarajapu Journal: Am J Physiol Heart Circ Physiol Date: 2015-09-18 Impact factor: 4.733
Authors: Sonia Zambrano; Antonio Jesús Blanca; María Victoria Ruiz-Armenta; José Luis Miguel-Carrasco; Elisa Revilla; Consuelo Santa-María; Alfonso Mate; Carmen María Vázquez Journal: Eur J Nutr Date: 2012-12-06 Impact factor: 5.614
Authors: Erin R Rademacher; David R Jacobs; Antoinette Moran; Julia Steinberger; Ronald J Prineas; Alan Sinaiko Journal: J Hypertens Date: 2009-09 Impact factor: 4.844