Impaired neuronal nitric oxide synthase-mediated vasodilator responses to mental stress in essential hypertension
In: Hypertension (Dallas, Tex. : 1979), Jg. 65 (2015-03-04), Heft 4
Online
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Zugriff:
Neuronal NO synthase (nNOS) regulates blood flow in resistance vasculature at rest and during mental stress. To investigate whether nNOS signaling is dysfunctional in essential hypertension, forearm blood flow responses to mental stress were examined in 88 subjects: 48 with essential hypertension (42±14 years; blood pressure, 141±17/85±15 mm Hg; mean±SD) and 40 normotensive controls (38±14 years; 117±13/74±9 mm Hg). A subsample of 34 subjects (17 hypertensive) participated in a single blind 2-phase crossover study, in which placebo or sildenafil 50 mg PO was administered before an intrabrachial artery infusion of the selective nNOS inhibitor S-methyl- l -thiocitrulline (SMTC, 0.05, 0.1, and 0.2 μmol/min) at rest and during mental stress. In a further subsample (n=21) with an impaired blood flow response to mental stress, responses were measured in the presence and absence of the α-adrenergic antagonist phentolamine. The blood flow response to mental stress was impaired in hypertensive compared with normotensive subjects (37±7% versus 70±8% increase over baseline; P P =0.01, between groups). Sildenafil reduced the blood flow response to stress in normotensive subjects from 89±14% to 43±14% ( P P
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Impaired neuronal nitric oxide synthase-mediated vasodilator responses to mental stress in essential hypertension
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Autor/in / Beteiligte Person: | Shah, Ajay M. ; Chowienczyk, Philip ; Brett, Sally ; Fok, Henry ; Khan, Sitara ; Shabeeh, Husain ; Geer, Amber |
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Zeitschrift: | Hypertension (Dallas, Tex. : 1979), Jg. 65 (2015-03-04), Heft 4 |
Veröffentlichung: | 2015 |
Medientyp: | unknown |
ISSN: | 1524-4563 (print) |
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