Faculty Collaboration Database

Hypertension preserves the magnitude of microvascular flow-mediated dilation following transient elevation in intraluminal pressure. Physiol Rep 2021 Feb;9(3):e14507

Date

02/16/2021

Pubmed ID

33587335

Pubmed Central ID

PMC7883808

DOI

10.14814/phy2.14507

Scopus ID

2-s2.0-85100849665 (requires institutional sign-in at Scopus site)   2 Citations

Abstract

OBJECTIVE: The objective of this study was to measure flow-mediated dilation (FMD) prior to and following transient increases in intraluminal pressure (IILP) in resistance arterioles isolated from subjects with and without coronary artery disease (CAD) (CAD and non-CAD) and non-CAD subjects with hypertension.

METHODS: Arterioles were isolated from discarded surgical tissues (adipose and atrial) from patients without coronary artery disease (non-CAD; ≤1 risk factor, excluding hypertension), with CAD, and non-CAD patients with hypertension (hypertension as the only risk factor). To simulate transient hypertension, increased IILP was generated (150 mmHg, 30 min) by gravity. Arterioles were constricted with endothelin-1, followed by FMD and endothelial-independent dilation prior to and following exposure to IILP.

RESULTS: IILP reduced FMD in non-CAD and CAD arterioles relative to pre-IILP (p <.05 at 100 cmH₂ O). In contrast, arterioles from non-CAD hypertensive subjects exhibited no reduction in maximal FMD following IILP (p = .84 at 100 cmH₂ O). FMD was reduced by L-NAME prior to IILP in non-CAD hypertensive patients (p < .05 at 100 cmH₂ O); however, following IILP, FMD was inhibited by peg-cat (p < .05 at 100 cmH₂ O), indicating a switch from NO to H₂ O₂ as the mechanism of dilation.

CONCLUSIONS: Acute exposure (30 min) to IILP (150 mmHg) attenuates the magnitude of FMD in non-CAD and CAD resistance arterioles. The presence of clinically diagnosed hypertension in non-CAD resistance arterioles preserves the magnitude of FMD following IILP as a result of a compensatory switch from NO to H₂ O₂ as the mechanism of dilation.

Author List

Hughes WE, Zinkevich N, Gutterman DD, Beyer AM

Authors

Andreas M. Beyer PhD Associate Professor in the Medicine department at Medical College of Wisconsin
William E. Hughes Postdoctoral Fellow in the Medicine department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Adaptation, Physiological
Adipose Tissue
Adult
Aged
Arterial Pressure
Arterioles
Case-Control Studies
Coronary Artery Disease
Coronary Vessels
Female
Humans
Hydrogen Peroxide
Hypertension
Male
Microcirculation
Middle Aged
Nitric Oxide
Vasodilation