Format

Send to

Choose Destination
Am J Physiol Heart Circ Physiol. 2018 Jul 1;315(1):H18-H32. doi: 10.1152/ajpheart.00683.2017. Epub 2018 Mar 2.

Minoxidil improves vascular compliance, restores cerebral blood flow, and alters extracellular matrix gene expression in a model of chronic vascular stiffness.

Author information

1
National Heart, Lung, and Blood Institute, National Institutes of Health , Bethesda, Maryland.
2
Department of Cell Biology and Physiology, Washington University School of Medicine , St. Louis, Missouri.
3
Department of Radiology, Washington University School of Medicine , St. Louis, Missouri.
4
Department of Internal Medicine, Washington University School of Medicine , St. Louis, Missouri.
5
Department of Pediatrics, Washington University School of Medicine , St. Louis, Missouri.
6
Department of Biomedical Engineering, Washington University in St. Louis , St. Louis, Missouri; Department of Pediatrics, Children's National Medical Center, Washington, D.C.

Abstract

Increased vascular stiffness correlates with a higher risk of cardiovascular complications in aging adults. Elastin (ELN) insufficiency, as observed in patients with Williams-Beuren syndrome or with familial supravalvular aortic stenosis, also increases vascular stiffness and leads to arterial narrowing. We used Eln+/- mice to test the hypothesis that pathologically increased vascular stiffness with concomitant arterial narrowing leads to decreased blood flow to end organs such as the brain. We also hypothesized that drugs that remodel arteries and increase lumen diameter would improve flow. To test these hypotheses, we compared carotid blood flow using ultrasound and cerebral blood flow using MRI-based arterial spin labeling in wild-type (WT) and Eln+/- mice. We then studied how minoxidil, an ATP-sensitive K+ channel opener and vasodilator, affects vessel mechanics, blood flow, and gene expression. Both carotid and cerebral blood flows were lower in Eln+/- mice than in WT mice. Treatment of Eln+/- mice with minoxidil lowered blood pressure and reduced functional arterial stiffness to WT levels. Minoxidil also improved arterial diameter and restored carotid and cerebral blood flows in Eln+/- mice. The beneficial effects persisted for weeks after drug removal. RNA-Seq analysis revealed differential expression of 127 extracellular matrix-related genes among the treatment groups. These results indicate that ELN insufficiency impairs end-organ perfusion, which may contribute to the increased cardiovascular risk. Minoxidil, despite lowering blood pressure, improves end-organ perfusion. Changes in matrix gene expression and persistence of treatment effects after drug withdrawal suggest arterial remodeling. Such remodeling may benefit patients with genetic or age-dependent ELN insufficiency. NEW & NOTEWORTHY Our work with a model of chronic vascular stiffness, the elastin ( Eln)+/- mouse, shows reduced brain perfusion as measured by carotid ultrasound and MRI arterial spin labeling. Vessel caliber, functional stiffness, and blood flow improved with minoxidil. The ATP-sensitive K+ channel opener increased Eln gene expression and altered 126 other matrix-associated genes.

KEYWORDS:

ATP-sensitive K+ channel; arterial stiffness; cerebral blood flow; elastin; extracellular matrix; vascular remodeling

PMID:
29498532
PMCID:
PMC6087770
DOI:
10.1152/ajpheart.00683.2017
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Atypon Icon for PubMed Central
Loading ...
Support Center