Greater impairments in cerebral artery compared with skeletal muscle feed artery endothelial function in a mouse model of increased large artery stiffness. (20th February 2015)

• Record Type: Journal Article
• Authors: Walker, Ashley E.; Henson, Grant D.; Reihl, Kelly D.; Morgan, R. Garrett; Dobson, Parker S.; Nielson, Elizabeth I.; Ling, Jing; Mecham, Robert P.; Li, Dean Y.; Lesniewski, Lisa A.; Donato, Anthony J.
• Is Part Of: Journal of physiology. Volume 593:Number 8(2015:Apr.)
• Page Start: 1931
• Page End: 1943
• Publication Date: 2015-02-20
• Subjects: Physiology -- Periodicals; 612.005
• DOI: 10.1113/jphysiol.2014.285338
• Languages: English
• ISSNs: 0022-3751

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="tjp6564-sec-0010" sec-type="section"> <title>Key points</title> <p> <list id="tjp6564-list-0001" list-type="bullet"> <list-item> <p>Increased large artery stiffness is a hallmark of arterial dysfunction with advancing age and is also present in other disease conditions such as diabetes. Increased large artery stiffness is correlated with resistance artery dysfunction in humans.</p> </list-item> <list-item> <p>Using a mouse model of altered arterial elastin content, this is the first study to examine the cause‐and‐effect relationship between large artery stiffness and peripheral resistance artery function.</p> </list-item> <list-item> <p>Our results indicate that mice with genetically greater large artery stiffness have impaired cerebral artery endothelial function, but generally preserved skeletal muscle feed artery endothelial function. The mechanisms for impaired cerebral artery endothelial function are reduced nitric oxide bioavailability and increased oxidative stress.</p> </list-item> <list-item> <p>These findings suggest that interventions that target large artery stiffness may be important to reduce disease risk associated with cerebral artery dysfunction in conditions such as advancing age.</p> </list-item> </list> </p> </sec> <sec id="tjp6564-sec-0020" sec-type="section"> <title>Abstract</title> <p>Advancing age as well as diseases such as diabetes are characterized by both increased large artery stiffness and impaired peripheral artery function. It has been hypothesized that greater large artery stiffness causes peripheral artery dysfunction; however, a cause‐and‐effect relationship has not previously been established. We used elastin heterozygote mice (<italic>Eln</italic><sup>+/–</sup>) as a model of increased large artery stiffness without co‐morbidities unrelated to the large artery properties. Aortic stiffness, measured by pulse wave velocity, was ∼35% greater in <italic>Eln</italic><sup>+/–</sup> mice than in wild‐type (<italic>Eln</italic><sup>+/+</sup>) mice (<italic>P</italic> = 0.04). Endothelium‐dependent dilatation (EDD), assessed by the maximal dilatation to acetylcholine, was ∼40% lower in <italic>Eln</italic><sup>+/–</sup> than <italic>Eln</italic><sup>+/+</sup> mice in the middle cerebral artery (MCA, <italic>P</italic> < 0.001), but was similar between groups in the gastrocnemius feed arteries (GFA, <italic>P</italic> = 0.79). In the MCA, EDD did not differ between groups after incubation with the nitric oxide (NO) synthase inhibitor <italic>N</italic><sup>ω</sup>‐nitro‐<sc>l</sc>‐arginine methyl ester (<italic>P</italic> > 0.05), indicating that lower NO bioavailability contributed to the impaired EDD in <italic>Eln</italic><sup>+/–</sup> mice. Superoxide production and content of the oxidative stress marker nitrotyrosine was higher in MCAs from <italic>Eln<sup>+/−</sup></italic> compared with <italic>Eln</italic><sup>+/+</sup> mice (<italic>P</italic> < 0.05). In the MCA, after incubation with the superoxide scavenger TEMPOL, maximal EDD improved by ∼65% in <italic>Eln</italic><sup>+/–</sup> (<italic>P</italic> = 0.002), but was unchanged in <italic>Eln</italic><sup>+/+</sup> mice (<italic>P</italic> = 0.17). These results indicate that greater large artery stiffness has a more profound effect on endothelial function in cerebral arteries compared with skeletal muscle feed arteries. Greater large artery stiffness can cause cerebral artery endothelial dysfunction by reducing NO bioavailability and increasing oxidative stress.</p> </sec> </abstract>