The role of the endothelium in the hyperemic response to passive leg movement : looking beyond nitric oxide

Passive leg movement (PLM) evokes a robust and predominantly nitric oxide (NO)-mediated increase in blood flow that declines with age and disease. Consequently, PLM is becoming increasingly accepted as a sensitive assessment of endothelium-mediated vascular function. However, a substantial PLM-induced hyperemic response is still evoked despite nitric oxide synthase (NOS) inhibition. Therefore, in nine young healthy men (25 ± 4 yr), this investigation aimed to determine whether the combination of two potent endothelium-dependent vasodilators, specifically prostaglandin (PG) and endothelium-derived hyperpolarizing factor (EDHF), account for the remaining hyperemic response to the two variants of PLM, PLM (60 movements) and single PLM (sPLM, 1 movement), when NOS is inhibited. The leg blood flow (LBF, Doppler ultrasound) response to PLM and sPLM following the intra-arterial infusion of NG-monomethyl-l-arginine (l-NMMA), to inhibit NOS, was compared to the combined inhibition of NOS, cyclooxygenase (COX), and cytochrome P-450 (CYP450) by l-NMMA, ketorolac tromethamine (KET), and fluconazole (FLUC), respectively. NOS inhibition attenuated the overall LBF [area under the curve (LBFAUC)] response to both PLM (control: 456 ± 194, l-NMMA: 168 ± 127 mL, P < 0.01) and sPLM (control: 185 ± 171, l-NMMA: 62 ± 31 mL, P = 0.03). The combined inhibition of NOS, COX, and CYP450 (i.e., l-NMMA+KET+FLUC) did not further attenuate the hyperemic responses to PLM (LBFAUC: 271 ± 97 mL, P > 0.05) or sPLM (LBFAUC: 72 ± 45 mL, P > 0.05). Therefore, PG and EDHF do not collectively contribute to the non-NOS-derived NO-mediated, endothelium-dependent hyperemic response to either PLM or sPLM in healthy young men. These findings add to the mounting evidence and understanding of the vasodilatory pathways assessed by the PLM and sPLM vascular function tests.NEW & NOTEWORTHY Passive leg movement (PLM) evokes a highly nitric oxide (NO)-mediated hyperemic response and may provide a novel evaluation of vascular function. The contributions of endothelium-dependent vasodilatory pathways, beyond NO and including prostaglandins and endothelium-derived hyperpolarizing factor, to the PLM-induced hyperemic response to PLM have not been evaluated. With intra-arterial drug infusion, the combined inhibition of nitric oxide synthase (NOS), cyclooxygenase, and cytochrome P-450 (CYP450) pathways did not further diminish the hyperemic response to PLM compared with NOS inhibition alone.

Medienart:

E-Artikel

Erscheinungsjahr:

2021

Erschienen:

2021

Enthalten in:

Zur Gesamtaufnahme - volume:320

Enthalten in:

American journal of physiology. Heart and circulatory physiology - 320(2021), 2 vom: 01. Feb., Seite H668-H678

Sprache:

Englisch

Beteiligte Personen:

Trinity, Joel D [VerfasserIn]
Kwon, Oh Sung [VerfasserIn]
Broxterman, Ryan M [VerfasserIn]
Gifford, Jayson R [VerfasserIn]
Kithas, Andrew C [VerfasserIn]
Hydren, Jay R [VerfasserIn]
Jarrett, Catherine L [VerfasserIn]
Shields, Katherine L [VerfasserIn]
Bisconti, Angela V [VerfasserIn]
Park, Soung Hun [VerfasserIn]
Craig, Jesse C [VerfasserIn]
Nelson, Ashley D [VerfasserIn]
Morgan, David E [VerfasserIn]
Jessop, Jacob E [VerfasserIn]
Bledsoe, Amber D [VerfasserIn]
Richardson, Russell S [VerfasserIn]

Links:

Volltext

Themen:

31C4KY9ESH
Biological Factors
Comparative Study
Cyclooxygenase Inhibitors
Cytochrome P-450 Enzyme Inhibitors
EC 1.14.13.39
Endothelium-dependent hyperpolarization factor
Journal Article
Nitric Oxide
Nitric Oxide Synthase
Nitric oxide
Prostaglandins
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.
Vascular function
Vasodilation

Anmerkungen:

Date Completed 22.03.2021

Date Revised 02.02.2022

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1152/ajpheart.00784.2020

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM318717794