Mesenteric arteries from stroke-prone spontaneously hypertensive rats exhibit an increase in nitric-oxide-dependent vasorelaxation

Brandi M. Wynne, Hicham Labazi, Victor V. Lima, Fernando S. Carneiro, R Clinton Webb, Rita C. Tostes, Fernanda R. Giachini

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

The endothelium is crucial for the maintenance of vascular tone by releasing several vasoactive substances, including nitric oxide (NO). Systemic mean arterial pressure is primarily regulated by the resistance vasculature, which has been shown to exhibit increased vascular reactivity, and decreased vasorelaxation during hypertension. Here, we aimed to determine the mechanism for mesenteric artery vasorelaxation of the stroke-prone spontaneously hypertensive rat (SHRSP). We hypothesized that endothelial NO synthase (eNOS) is upregulated in SHRSP vessels, increasing NO production to compensate for the endothelial dysfunction. Concentration–response curves to acetylcholine (ACh) were performed in second-order mesenteric arteries; we observed decreased relaxation responses to ACh (maximum effect elicited by the agonist) as compared with Wistar-Kyoto (WKY) controls. Vessels from SHRSP incubated with Nω-nitro-L-arginine methyl ester and (or) indomethacin exhibited decreased ACh-mediated relaxation, suggesting a primary role for NO-dependent relaxation. Vessels from SHRSP exhibited a significantly decreased relaxation response with inducible NO synthase (iNOS) inhibition, as compared with WKY vessels. Western blot analysis showed increased total phosphorylated NF-κB, and phosphorylated and total eNOS in SHRSP vessels. Overall, these data suggest a compensatory role for NO by increased eNOS activation. Moreover, we believe that iNOS, although increasing NO bioavailability to compensate for decreased relaxation, leads to a cycle of further endothelial dysfunction in SHRSP mesenteric arteries.

Original languageEnglish (US)
Pages (from-to)719-727
Number of pages9
JournalCanadian Journal of Physiology and Pharmacology
Volume96
Issue number8
DOIs
StatePublished - Jan 1 2018

Fingerprint

Mesenteric Arteries
Inbred SHR Rats
Vasodilation
Nitric Oxide
Stroke
Nitric Oxide Synthase
Acetylcholine
Blood Vessels
Nitric Oxide Synthase Type III
Nitric Oxide Synthase Type II
Indomethacin
Biological Availability
Endothelium
Arterial Pressure
Western Blotting
Maintenance
Hypertension

Keywords

  • Hypertension
  • Inducible nitric oxide synthase
  • SHRSP
  • Vascular

ASJC Scopus subject areas

  • Physiology
  • Pharmacology
  • Physiology (medical)

Cite this

Mesenteric arteries from stroke-prone spontaneously hypertensive rats exhibit an increase in nitric-oxide-dependent vasorelaxation. / Wynne, Brandi M.; Labazi, Hicham; Lima, Victor V.; Carneiro, Fernando S.; Webb, R Clinton; Tostes, Rita C.; Giachini, Fernanda R.

In: Canadian Journal of Physiology and Pharmacology, Vol. 96, No. 8, 01.01.2018, p. 719-727.

Research output: Contribution to journalArticle

Wynne, Brandi M. ; Labazi, Hicham ; Lima, Victor V. ; Carneiro, Fernando S. ; Webb, R Clinton ; Tostes, Rita C. ; Giachini, Fernanda R. / Mesenteric arteries from stroke-prone spontaneously hypertensive rats exhibit an increase in nitric-oxide-dependent vasorelaxation. In: Canadian Journal of Physiology and Pharmacology. 2018 ; Vol. 96, No. 8. pp. 719-727.
@article{4583e9c3b483449688192fd939e2f8c8,
title = "Mesenteric arteries from stroke-prone spontaneously hypertensive rats exhibit an increase in nitric-oxide-dependent vasorelaxation",
abstract = "The endothelium is crucial for the maintenance of vascular tone by releasing several vasoactive substances, including nitric oxide (NO). Systemic mean arterial pressure is primarily regulated by the resistance vasculature, which has been shown to exhibit increased vascular reactivity, and decreased vasorelaxation during hypertension. Here, we aimed to determine the mechanism for mesenteric artery vasorelaxation of the stroke-prone spontaneously hypertensive rat (SHRSP). We hypothesized that endothelial NO synthase (eNOS) is upregulated in SHRSP vessels, increasing NO production to compensate for the endothelial dysfunction. Concentration–response curves to acetylcholine (ACh) were performed in second-order mesenteric arteries; we observed decreased relaxation responses to ACh (maximum effect elicited by the agonist) as compared with Wistar-Kyoto (WKY) controls. Vessels from SHRSP incubated with Nω-nitro-L-arginine methyl ester and (or) indomethacin exhibited decreased ACh-mediated relaxation, suggesting a primary role for NO-dependent relaxation. Vessels from SHRSP exhibited a significantly decreased relaxation response with inducible NO synthase (iNOS) inhibition, as compared with WKY vessels. Western blot analysis showed increased total phosphorylated NF-κB, and phosphorylated and total eNOS in SHRSP vessels. Overall, these data suggest a compensatory role for NO by increased eNOS activation. Moreover, we believe that iNOS, although increasing NO bioavailability to compensate for decreased relaxation, leads to a cycle of further endothelial dysfunction in SHRSP mesenteric arteries.",
keywords = "Hypertension, Inducible nitric oxide synthase, SHRSP, Vascular",
author = "Wynne, {Brandi M.} and Hicham Labazi and Lima, {Victor V.} and Carneiro, {Fernando S.} and Webb, {R Clinton} and Tostes, {Rita C.} and Giachini, {Fernanda R.}",
year = "2018",
month = "1",
day = "1",
doi = "10.1139/cjpp-2017-0477",
language = "English (US)",
volume = "96",
pages = "719--727",
journal = "Canadian Journal of Physiology and Pharmacology",
issn = "0008-4212",
publisher = "National Research Council of Canada",
number = "8",

}

TY - JOUR

T1 - Mesenteric arteries from stroke-prone spontaneously hypertensive rats exhibit an increase in nitric-oxide-dependent vasorelaxation

AU - Wynne, Brandi M.

AU - Labazi, Hicham

AU - Lima, Victor V.

AU - Carneiro, Fernando S.

AU - Webb, R Clinton

AU - Tostes, Rita C.

AU - Giachini, Fernanda R.

PY - 2018/1/1

Y1 - 2018/1/1

N2 - The endothelium is crucial for the maintenance of vascular tone by releasing several vasoactive substances, including nitric oxide (NO). Systemic mean arterial pressure is primarily regulated by the resistance vasculature, which has been shown to exhibit increased vascular reactivity, and decreased vasorelaxation during hypertension. Here, we aimed to determine the mechanism for mesenteric artery vasorelaxation of the stroke-prone spontaneously hypertensive rat (SHRSP). We hypothesized that endothelial NO synthase (eNOS) is upregulated in SHRSP vessels, increasing NO production to compensate for the endothelial dysfunction. Concentration–response curves to acetylcholine (ACh) were performed in second-order mesenteric arteries; we observed decreased relaxation responses to ACh (maximum effect elicited by the agonist) as compared with Wistar-Kyoto (WKY) controls. Vessels from SHRSP incubated with Nω-nitro-L-arginine methyl ester and (or) indomethacin exhibited decreased ACh-mediated relaxation, suggesting a primary role for NO-dependent relaxation. Vessels from SHRSP exhibited a significantly decreased relaxation response with inducible NO synthase (iNOS) inhibition, as compared with WKY vessels. Western blot analysis showed increased total phosphorylated NF-κB, and phosphorylated and total eNOS in SHRSP vessels. Overall, these data suggest a compensatory role for NO by increased eNOS activation. Moreover, we believe that iNOS, although increasing NO bioavailability to compensate for decreased relaxation, leads to a cycle of further endothelial dysfunction in SHRSP mesenteric arteries.

AB - The endothelium is crucial for the maintenance of vascular tone by releasing several vasoactive substances, including nitric oxide (NO). Systemic mean arterial pressure is primarily regulated by the resistance vasculature, which has been shown to exhibit increased vascular reactivity, and decreased vasorelaxation during hypertension. Here, we aimed to determine the mechanism for mesenteric artery vasorelaxation of the stroke-prone spontaneously hypertensive rat (SHRSP). We hypothesized that endothelial NO synthase (eNOS) is upregulated in SHRSP vessels, increasing NO production to compensate for the endothelial dysfunction. Concentration–response curves to acetylcholine (ACh) were performed in second-order mesenteric arteries; we observed decreased relaxation responses to ACh (maximum effect elicited by the agonist) as compared with Wistar-Kyoto (WKY) controls. Vessels from SHRSP incubated with Nω-nitro-L-arginine methyl ester and (or) indomethacin exhibited decreased ACh-mediated relaxation, suggesting a primary role for NO-dependent relaxation. Vessels from SHRSP exhibited a significantly decreased relaxation response with inducible NO synthase (iNOS) inhibition, as compared with WKY vessels. Western blot analysis showed increased total phosphorylated NF-κB, and phosphorylated and total eNOS in SHRSP vessels. Overall, these data suggest a compensatory role for NO by increased eNOS activation. Moreover, we believe that iNOS, although increasing NO bioavailability to compensate for decreased relaxation, leads to a cycle of further endothelial dysfunction in SHRSP mesenteric arteries.

KW - Hypertension

KW - Inducible nitric oxide synthase

KW - SHRSP

KW - Vascular

UR - http://www.scopus.com/inward/record.url?scp=85050915826&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85050915826&partnerID=8YFLogxK

U2 - 10.1139/cjpp-2017-0477

DO - 10.1139/cjpp-2017-0477

M3 - Article

C2 - 29430946

AN - SCOPUS:85050915826

VL - 96

SP - 719

EP - 727

JO - Canadian Journal of Physiology and Pharmacology

JF - Canadian Journal of Physiology and Pharmacology

SN - 0008-4212

IS - 8

ER -