Disruption of Physiological Balance between Nitric Oxide and Endothelium-Dependent Hyperpolarization Impairs Cardiovascular Homeostasis in Mice

Shigeo Godo, Ayuko Sawada, Hiroki Saito, Shohei Ikeda, Budbazar Enkhjargal, Kota Suzuki, Shuhei Tanaka, Hiroaki Shimokawa

Research output: Contribution to journalArticlepeer-review

34 Citations (Scopus)

Abstract

Objective-Endothelium-derived nitric oxide (NO) and endothelium-dependent hyperpolarization (EDH) play important roles in modulating vascular tone in a distinct vessel size-dependent manner; NO plays a dominant role in conduit arteries and EDH in resistance vessels. We have recently demonstrated that endothelial NO synthase (eNOS) is functionally suppressed in resistance vessels through caveolin-1 (Cav-1)-dependent mechanism, switching its function from NO to EDH/hydrogen peroxide generation in mice. Here, we examined the possible importance of the physiological balance between NO and EDH in cardiovascular homeostasis. Approach and Results-We used 2 genotypes of mice in which eNOS activity is genetically upregulated; Cav-1-knockout (Cav-1-KO) and endothelium-specific eNOS transgenic (eNOS-Tg) mice. Isometric tension recordings and Langendorff experiments with isolated perfused hearts showed that NO-mediated relaxations were significantly enhanced, whereas EDH-mediated relaxations were markedly reduced in microcirculations. Importantly, impaired EDH-mediated relaxations of small mesenteric arteries from Cav-1-KO mice were completely rescued by crossing the mice with those with endothelium-specific overexpression of Cav-1. Furthermore, both genotypes showed altered cardiovascular phenotypes, including cardiac hypertrophy in Cav-1-KO mice and hypotension in eNOS-Tg mice. Finally, we examined cardiac responses to chronic pressure overload by transverse aortic constriction in vivo. When compared with wild-type mice, both Cav-1-KO and eNOS-Tg mice exhibited reduced survival after transverse aortic constriction associated with accelerated left ventricular systolic dysfunction, reduced coronary flow reserve, and enhanced myocardial hypoxia. Conclusions-These results indicate that excessive endothelium-derived NO with reduced EDH impairs cardiovascular homeostasis in mice in vivo.

Original languageEnglish
Pages (from-to)97-107
Number of pages11
JournalArteriosclerosis, thrombosis, and vascular biology
Volume36
Issue number1
DOIs
Publication statusPublished - 2016 Jan 1

Keywords

  • caveolin-1
  • endothelium
  • endothelium-dependent hyperpolarization factor
  • nitric oxide

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine

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