Vitamins Reverse Endothelial Dysfunction Through Regulation of eNOS and NAD(P)H Oxidase Activities
Antioxidant vitamins C and E have protective properties in genetic hypertension associated with enhanced oxidative stress. This study investigated whether vitamins C and/or E modulate vascular function by regulating enzymatic activities of endothelial nitric oxide synthase (eNOS) and NAD(P)H oxida...
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| Format: | Article |
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American Heart Association
2003
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| Online Access: | https://eprints.nottingham.ac.uk/426/ |
| _version_ | 1848790410818748416 |
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| author | Ulker, Sible McKeown, Pascal Bayraktutan, Ulvi |
| author_facet | Ulker, Sible McKeown, Pascal Bayraktutan, Ulvi |
| author_sort | Ulker, Sible |
| building | Nottingham Research Data Repository |
| collection | Online Access |
| description | Antioxidant vitamins C and E have protective properties in genetic hypertension associated with enhanced
oxidative stress. This study investigated whether vitamins C and/or E modulate vascular function by regulating
enzymatic activities of endothelial nitric oxide synthase (eNOS) and NAD(P)H oxidase using thoracic aortas of 20- to
22-week-old male spontaneously hypertensive rats (SHR) and their matched normotensive counterparts, Wistar-Kyoto
rats (WKY). SHR aortas had impaired relaxant responses to acetylcholine but not to sodium nitroprusside, despite an
2-fold increase in eNOS activity and NO release. The levels of superoxide anion (O2
), a potent NO scavenger, and
NAD(P)H oxidase activity were also 2-fold higher in SHR aortas. Mechanical but not pharmacological inactivation of
endothelium (by rubbing and 100 mol/L L-NAME, respectively) significantly abrogated O2
in both strains.
Treatments of SHR aortas with NAD(P)H oxidase inhibitors, namely diphenyleneiodinium and apocynin, significantly
diminished O2
production. The incubation of SHR aortas with different concentrations of vitamin C (10 to 100 mol/L)
and specifically with high concentrations of vitamin E (100 mol/L) improved endothelial function, reduced superoxide
production as well as NAD(P)H oxidase activity, and increased eNOS activity and NO generation in SHR aortas to the
levels observed in vitamin C- and E-treated WKY aortas. Our results reveal endothelial NAD(P)H oxidase as the major
source of vascular O2
in SHR and also show that vitamins C and E are critical in normalizing genetic endothelial
dysfunction through regulation of eNOS and NAD(P)H oxidase activities. |
| first_indexed | 2025-11-14T18:12:11Z |
| format | Article |
| id | nottingham-426 |
| institution | University of Nottingham Malaysia Campus |
| institution_category | Local University |
| last_indexed | 2025-11-14T18:12:11Z |
| publishDate | 2003 |
| publisher | American Heart Association |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | nottingham-4262020-05-04T20:32:08Z https://eprints.nottingham.ac.uk/426/ Vitamins Reverse Endothelial Dysfunction Through Regulation of eNOS and NAD(P)H Oxidase Activities Ulker, Sible McKeown, Pascal Bayraktutan, Ulvi Antioxidant vitamins C and E have protective properties in genetic hypertension associated with enhanced oxidative stress. This study investigated whether vitamins C and/or E modulate vascular function by regulating enzymatic activities of endothelial nitric oxide synthase (eNOS) and NAD(P)H oxidase using thoracic aortas of 20- to 22-week-old male spontaneously hypertensive rats (SHR) and their matched normotensive counterparts, Wistar-Kyoto rats (WKY). SHR aortas had impaired relaxant responses to acetylcholine but not to sodium nitroprusside, despite an 2-fold increase in eNOS activity and NO release. The levels of superoxide anion (O2 ), a potent NO scavenger, and NAD(P)H oxidase activity were also 2-fold higher in SHR aortas. Mechanical but not pharmacological inactivation of endothelium (by rubbing and 100 mol/L L-NAME, respectively) significantly abrogated O2 in both strains. Treatments of SHR aortas with NAD(P)H oxidase inhibitors, namely diphenyleneiodinium and apocynin, significantly diminished O2 production. The incubation of SHR aortas with different concentrations of vitamin C (10 to 100 mol/L) and specifically with high concentrations of vitamin E (100 mol/L) improved endothelial function, reduced superoxide production as well as NAD(P)H oxidase activity, and increased eNOS activity and NO generation in SHR aortas to the levels observed in vitamin C- and E-treated WKY aortas. Our results reveal endothelial NAD(P)H oxidase as the major source of vascular O2 in SHR and also show that vitamins C and E are critical in normalizing genetic endothelial dysfunction through regulation of eNOS and NAD(P)H oxidase activities. American Heart Association 2003 Article PeerReviewed Ulker, Sible, McKeown, Pascal and Bayraktutan, Ulvi (2003) Vitamins Reverse Endothelial Dysfunction Through Regulation of eNOS and NAD(P)H Oxidase Activities. Hypertension, 41 . pp. 534-539. nitric oxide endothelium enzymes antioxidants hypertension experimental vitamins |
| spellingShingle | nitric oxide endothelium enzymes antioxidants hypertension experimental vitamins Ulker, Sible McKeown, Pascal Bayraktutan, Ulvi Vitamins Reverse Endothelial Dysfunction Through Regulation of eNOS and NAD(P)H Oxidase Activities |
| title | Vitamins Reverse Endothelial Dysfunction Through
Regulation of eNOS and NAD(P)H Oxidase Activities |
| title_full | Vitamins Reverse Endothelial Dysfunction Through
Regulation of eNOS and NAD(P)H Oxidase Activities |
| title_fullStr | Vitamins Reverse Endothelial Dysfunction Through
Regulation of eNOS and NAD(P)H Oxidase Activities |
| title_full_unstemmed | Vitamins Reverse Endothelial Dysfunction Through
Regulation of eNOS and NAD(P)H Oxidase Activities |
| title_short | Vitamins Reverse Endothelial Dysfunction Through
Regulation of eNOS and NAD(P)H Oxidase Activities |
| title_sort | vitamins reverse endothelial dysfunction through
regulation of enos and nad(p)h oxidase activities |
| topic | nitric oxide endothelium enzymes antioxidants hypertension experimental vitamins |
| url | https://eprints.nottingham.ac.uk/426/ |