Differences in vascular nitric oxide and endothelium-derived hyperpolarizing factor bioavailability in blacks and whites

Muhiddin A. Ozkor, Ayaz M. Rahman, Jonathan R. Murrow, Nino Kavtaradze, Ji Lin, Amita Manatunga, Salim Hayek, Arshed A. Quyyumi

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

Objective-Abnormalities in nitric oxide (NO) bioavailability have been reported in blacks. Whether there are differences in endothelium-derived hyperpolarizing factor (EDHF) in addition to NO between blacks and whites and how these affect physiological vasodilation remain unknown. We hypothesized that the bioavailability of vascular NO and EDHF, at rest and with pharmacological and physiological vasodilation, varies between whites and blacks. Approach and Results-In 74 white and 86 black subjects without known cardiovascular disease risk factors, forearm blood flow was measured using plethysmography at rest and during inhibition of NO with NG-monomethyl-L-arginine and of K +Ca channels (EDHF) with tetraethylammonium. The reduction in resting forearm blood flow was greater with NG-monomethyl-L- arginine (P=0.019) and similar with tetraethylammonium in whites compared with blacks. Vasodilation with bradykinin, acetylcholine, and sodium nitroprusside was lower in blacks compared with whites (all P<0.0001). Inhibition with NG-monomethyl-L-arginine was greater in whites compared with blacks with bradykinin, acetylcholine, and exercise. Inhibition with tetraethylammonium was lower in blacks with bradykinin, but greater during exercise and with acetylcholine. Conclusions-The contribution to both resting and stimulus-mediated vasodilator tone of NO is greater in whites compared with blacks. EDHF partly compensates for the reduced NO release in exercise and acetylcholine-mediated vasodilation in blacks. Preserved EDHF but reduced NO bioavailability and sensitivity characterizes the vasculature in healthy blacks.

Original languageEnglish (US)
Pages (from-to)1320-1327
Number of pages8
JournalArteriosclerosis, thrombosis, and vascular biology
Volume34
Issue number6
DOIs
StatePublished - Jun 2014

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Biological Availability
Blood Vessels
Nitric Oxide
omega-N-Methylarginine
Vasodilation
Acetylcholine
Tetraethylammonium
Endothelium
Bradykinin
Exercise
Forearm
Plethysmography
hydroquinone
Nitroprusside
Vasodilator Agents
Cardiovascular Diseases
Pharmacology

Keywords

  • African Americans
  • EDHF
  • exercise
  • nitric oxide
  • vasodilation

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine

Cite this

Differences in vascular nitric oxide and endothelium-derived hyperpolarizing factor bioavailability in blacks and whites. / Ozkor, Muhiddin A.; Rahman, Ayaz M.; Murrow, Jonathan R.; Kavtaradze, Nino; Lin, Ji; Manatunga, Amita; Hayek, Salim; Quyyumi, Arshed A.

In: Arteriosclerosis, thrombosis, and vascular biology, Vol. 34, No. 6, 06.2014, p. 1320-1327.

Research output: Contribution to journalArticle

Ozkor, Muhiddin A. ; Rahman, Ayaz M. ; Murrow, Jonathan R. ; Kavtaradze, Nino ; Lin, Ji ; Manatunga, Amita ; Hayek, Salim ; Quyyumi, Arshed A. / Differences in vascular nitric oxide and endothelium-derived hyperpolarizing factor bioavailability in blacks and whites. In: Arteriosclerosis, thrombosis, and vascular biology. 2014 ; Vol. 34, No. 6. pp. 1320-1327.
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abstract = "Objective-Abnormalities in nitric oxide (NO) bioavailability have been reported in blacks. Whether there are differences in endothelium-derived hyperpolarizing factor (EDHF) in addition to NO between blacks and whites and how these affect physiological vasodilation remain unknown. We hypothesized that the bioavailability of vascular NO and EDHF, at rest and with pharmacological and physiological vasodilation, varies between whites and blacks. Approach and Results-In 74 white and 86 black subjects without known cardiovascular disease risk factors, forearm blood flow was measured using plethysmography at rest and during inhibition of NO with NG-monomethyl-L-arginine and of K +Ca channels (EDHF) with tetraethylammonium. The reduction in resting forearm blood flow was greater with NG-monomethyl-L- arginine (P=0.019) and similar with tetraethylammonium in whites compared with blacks. Vasodilation with bradykinin, acetylcholine, and sodium nitroprusside was lower in blacks compared with whites (all P<0.0001). Inhibition with NG-monomethyl-L-arginine was greater in whites compared with blacks with bradykinin, acetylcholine, and exercise. Inhibition with tetraethylammonium was lower in blacks with bradykinin, but greater during exercise and with acetylcholine. Conclusions-The contribution to both resting and stimulus-mediated vasodilator tone of NO is greater in whites compared with blacks. EDHF partly compensates for the reduced NO release in exercise and acetylcholine-mediated vasodilation in blacks. Preserved EDHF but reduced NO bioavailability and sensitivity characterizes the vasculature in healthy blacks.",
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AU - Ozkor, Muhiddin A.

AU - Rahman, Ayaz M.

AU - Murrow, Jonathan R.

AU - Kavtaradze, Nino

AU - Lin, Ji

AU - Manatunga, Amita

AU - Hayek, Salim

AU - Quyyumi, Arshed A.

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N2 - Objective-Abnormalities in nitric oxide (NO) bioavailability have been reported in blacks. Whether there are differences in endothelium-derived hyperpolarizing factor (EDHF) in addition to NO between blacks and whites and how these affect physiological vasodilation remain unknown. We hypothesized that the bioavailability of vascular NO and EDHF, at rest and with pharmacological and physiological vasodilation, varies between whites and blacks. Approach and Results-In 74 white and 86 black subjects without known cardiovascular disease risk factors, forearm blood flow was measured using plethysmography at rest and during inhibition of NO with NG-monomethyl-L-arginine and of K +Ca channels (EDHF) with tetraethylammonium. The reduction in resting forearm blood flow was greater with NG-monomethyl-L- arginine (P=0.019) and similar with tetraethylammonium in whites compared with blacks. Vasodilation with bradykinin, acetylcholine, and sodium nitroprusside was lower in blacks compared with whites (all P<0.0001). Inhibition with NG-monomethyl-L-arginine was greater in whites compared with blacks with bradykinin, acetylcholine, and exercise. Inhibition with tetraethylammonium was lower in blacks with bradykinin, but greater during exercise and with acetylcholine. Conclusions-The contribution to both resting and stimulus-mediated vasodilator tone of NO is greater in whites compared with blacks. EDHF partly compensates for the reduced NO release in exercise and acetylcholine-mediated vasodilation in blacks. Preserved EDHF but reduced NO bioavailability and sensitivity characterizes the vasculature in healthy blacks.

AB - Objective-Abnormalities in nitric oxide (NO) bioavailability have been reported in blacks. Whether there are differences in endothelium-derived hyperpolarizing factor (EDHF) in addition to NO between blacks and whites and how these affect physiological vasodilation remain unknown. We hypothesized that the bioavailability of vascular NO and EDHF, at rest and with pharmacological and physiological vasodilation, varies between whites and blacks. Approach and Results-In 74 white and 86 black subjects without known cardiovascular disease risk factors, forearm blood flow was measured using plethysmography at rest and during inhibition of NO with NG-monomethyl-L-arginine and of K +Ca channels (EDHF) with tetraethylammonium. The reduction in resting forearm blood flow was greater with NG-monomethyl-L- arginine (P=0.019) and similar with tetraethylammonium in whites compared with blacks. Vasodilation with bradykinin, acetylcholine, and sodium nitroprusside was lower in blacks compared with whites (all P<0.0001). Inhibition with NG-monomethyl-L-arginine was greater in whites compared with blacks with bradykinin, acetylcholine, and exercise. Inhibition with tetraethylammonium was lower in blacks with bradykinin, but greater during exercise and with acetylcholine. Conclusions-The contribution to both resting and stimulus-mediated vasodilator tone of NO is greater in whites compared with blacks. EDHF partly compensates for the reduced NO release in exercise and acetylcholine-mediated vasodilation in blacks. Preserved EDHF but reduced NO bioavailability and sensitivity characterizes the vasculature in healthy blacks.

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