Cardiovascular effects of overexpression of endothelial nitric oxide synthase in the rostral ventrolateral medulla in stroke-prone spontaneously hypertensive rats

Takuya Kishi, Yoshitaka Hirooka, Koji Ito, Koji Sakai, Hiroaki Shimokawa, Akira Takeshita

Research output: Contribution to journalArticle

80 Citations (Scopus)

Abstract

We have previously demonstrated that the overexpression of endothelial NO synthase (eNOS) in the rostral ventrolateral medulla (RVLM) decreases blood pressure, heart rate, and sympathetic nerve activity via an increase in γ-amino butyric acid release in normotensive Wistar-Kyoto rats (WKY). Stroke-prone spontaneously hypertensive rats (SHRSP) appear to have reductions of NO production and GABA release in the RVLM. The aim of this study was to determine whether the effects of the increase in NO production in the RVLM in SHRSP are different from those in WKY. We transfected adenovirus vectors encoding either eNOS (AdeNOS) or β-galactosidase (Adβgal) into the RVLM of both strains. In the AdeNOS-treated group, mean arterial blood pressure and heart rate in the conscious state were significantly decreased at day 7 after the gene transfer in both strains. The decreases in mean arterial blood pressure and heart rate were significantly greater in SHRSP than in WKY. Urinary norepinephrine excretion was also decreased to a greater degree in SHRSP than in WKY after the gene transfer. The pressor response evoked by bicuculline into the RVLM of WKY was greater than that of SHRSP in the nontransfected group. However, in the AdeNOS-treated group, the pressor response did not differ between SHRSP and WKY after the gene transfer. These results indicate that the increase in NO production evoked by the overexpression of eNOS in the RVLM causes greater depressor and sympathoinhibitory responses in SHRSP than in WKY by improving an inhibitory action of GABA on the RVLM neurons.

Original languageEnglish
Pages (from-to)264-268
Number of pages5
JournalHypertension
Volume39
Issue number2 I
DOIs
Publication statusPublished - 2002 Mar 4
Externally publishedYes

Keywords

  • Brain
  • Cardiovascular diseases
  • Genes
  • Nitric oxide
  • Sympathetic nervous system

ASJC Scopus subject areas

  • Internal Medicine

Fingerprint Dive into the research topics of 'Cardiovascular effects of overexpression of endothelial nitric oxide synthase in the rostral ventrolateral medulla in stroke-prone spontaneously hypertensive rats'. Together they form a unique fingerprint.

  • Cite this