Back to Search
Start Over
Chronic vagal nerve stimulation prevents high-salt diet-induced endothelial dysfunction and aortic stiffening in stroke-prone spontaneously hypertensive rats
- Source :
- American Journal of Physiology-Heart and Circulatory Physiology. 311:H276-H285
- Publication Year :
- 2016
- Publisher :
- American Physiological Society, 2016.
-
Abstract
- Parasympathetic activity is often reduced in hypertension and can elicit anti-inflammatory mechanisms. Thus we hypothesized that chronic vagal nerve stimulation (VNS) may alleviate cardiovascular end-organ damage in stroke-prone spontaneously hypertensive rats. Vagal nerve stimulators were implanted, a high-salt diet initiated, and the stimulators turned on (VNS, n = 10) or left off (sham, n = 14) for 4 wk. Arterial pressure increased equally in both groups. After 4 wk, endothelial function, assessed by in vivo imaging of the long posterior ciliary artery (LPCA) after stimulation (pilocarpine) and inhibition ( Nω-nitro-l-arginine methyl ester) of endothelial nitric oxide synthase (eNOS), had significantly declined (−2.3 ± 1.2 μm, P < 0.05) in sham, but was maintained (−0.7 ± 0.8 μm, nonsignificant) in VNS. Furthermore, aortic eNOS activation (phosphorylated to total eNOS protein content ratio) was greater in VNS (0.83 ± 0.07) than in sham (0.47 ± 0.08, P < 0.05). After only 3 wk, ultrasound imaging of the aorta demonstrated decreased aortic strain (−9.7 ± 2.2%, P < 0.05) and distensibility (−2.39 ± 0.49 1,000/mmHg, P < 0.05) and increased pulse-wave velocity (+2.4 ± 0.7 m/s, P < 0.05) in sham but not in VNS (−3.8 ± 3.8%, −0.70 ± 1.4 1,000/mmHg, and +0.1 ± 0.7 m/s, all nonsignificant). Interleukin (IL)-6 serum concentrations tended to be higher in VNS than in sham (34.3 ± 8.3 vs. 16.1 ± 4.6 pg/ml, P = 0.06), and positive correlations were found between NO-dependent relaxation of the LPCA and serum levels of IL-6 ( r = +0.70, P < 0.05) and IL-10 (r = +0.56, P < 0.05) and between aortic eNOS activation and IL-10 ( r = +0.48, P < 0.05). In conclusion, chronic VNS prevents hypertension-induced endothelial dysfunction and aortic stiffening in an animal model of severe hypertension. We speculate that anti-inflammatory mechanisms may contribute to these effects. Listen to this article's corresponding podcast at http://ajpheart.podbean.com/e/chronic-vagal-nerve-stimulation-in-stroke-prone-shr/ .
- Subjects :
- Male
medicine.medical_specialty
Time Factors
Nitric Oxide Synthase Type III
Vagus Nerve Stimulation
Physiology
medicine.medical_treatment
Aorta, Thoracic
Vasodilation
Stimulation
030204 cardiovascular system & hematology
Nitric Oxide
Severity of Illness Index
Ciliary Arteries
03 medical and health sciences
Vascular Stiffness
Integrative Cardiovascular Physiology and Pathophysiology
0302 clinical medicine
Heart Rate
Rats, Inbred SHR
Physiology (medical)
medicine.artery
Internal medicine
Heart rate
medicine
Animals
Thoracic aorta
Arterial Pressure
Phosphorylation
Sodium Chloride, Dietary
Endothelial dysfunction
Stroke
Interleukin-6
business.industry
medicine.disease
Enzyme Activation
Disease Models, Animal
Implantable Neurostimulators
Blood pressure
Anesthesia
Hypertension
Cardiology
Endothelium, Vascular
Cardiology and Cardiovascular Medicine
business
030217 neurology & neurosurgery
Vagus nerve stimulation
Subjects
Details
- ISSN :
- 15221539 and 03636135
- Volume :
- 311
- Database :
- OpenAIRE
- Journal :
- American Journal of Physiology-Heart and Circulatory Physiology
- Accession number :
- edsair.doi.dedup.....f189425ed944061d596f11ec660237c4