Journal article
Autocrine/paracrine modulation of baroreceptor activity after antidromic stimulation of aortic depressor nerve in vivo
Autonomic neuroscience, Vol.180(1), pp.24-31
02/2014
DOI: 10.1016/j.autneu.2013.10.003
PMCID: PMC4100717
PMID: 24567955
Abstract
Activation of the sensory nerve endings of non-myelinated C-fiber afferents evokes release of autocrine/paracrine factors that cause localized vasodilation, neurogenic inflammation, and modulation of sensory nerve activity. The aims of this study were to determine the effect of antidromic electrical stimulation on afferent baroreceptor activity in vivo, and investigate the role of endogenous prostanoids and hydrogen peroxide (H2O2) in mediating changes in nerve activity. Baroreceptor activity was recorded from the left aortic depressor nerve (ADN) in anesthetized rats before and after stimulating the ADN for brief (5–20s) periods. The rostral end of the ADN was crushed or sectioned beforehand to prevent reflex changes in blood pressure. Antidromic stimulation of ADN using parameters that activate both myelinated A-fibers and non-myelinated C-fibers caused pronounced and long-lasting (>1min) inhibition of baroreceptor activity (n=9, P<0.05), with the magnitude and duration of inhibition dependent on the duration of the stimulation period (n=5). Baroreceptor activity was only transiently inhibited after selective stimulation of A-fibers. The inhibition of activity after antidromic stimulation of A and C fibers was prolonged after administration of the cyclooxygenase inhibitor indomethacin (5mg/kg, IV, n=7) and abolished after administration of PEG-catalase (104units/kg, IV, n=7), an enzyme that catalyzes the decomposition of H2O2 to water and oxygen. The results demonstrate a long-lasting inhibition of baroreceptor activity after antidromic stimulation of ADN and suggest that endogenous prostanoids and H2O2 oppose and mediate the inhibition, respectively. These mechanisms may contribute to rapid baroreceptor resetting during acute hypertension and be engaged during chronic baroreceptor activation therapy in patients with hypertension.
Details
- Title: Subtitle
- Autocrine/paracrine modulation of baroreceptor activity after antidromic stimulation of aortic depressor nerve in vivo
- Creators
- Valter J Santana-Filho - Department of Physiology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, BrazilGreg J Davis - Department of Internal Medicine, University of Iowa, USAJaci A Castania - Department of Physiology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, BrazilXiuying Ma - Department of Internal Medicine, University of Iowa, USAHelio C Salgado - Department of Physiology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, BrazilFrancois M Abboud - Department of Internal Medicine, University of Iowa, USARubens Fazan - Department of Physiology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, BrazilMark W Chapleau - Department of Internal Medicine, University of Iowa, USA
- Resource Type
- Journal article
- Publication Details
- Autonomic neuroscience, Vol.180(1), pp.24-31
- DOI
- 10.1016/j.autneu.2013.10.003
- PMID
- 24567955
- PMCID
- PMC4100717
- NLM abbreviation
- Auton Neurosci
- ISSN
- 1566-0702
- eISSN
- 1872-7484
- Publisher
- Elsevier BV
- Grant note
- name: FAPESP (Fundação de Amparo à Pesquisa do Estado de São Paulo, São Paulo, SP, Brazil); name: CAPES (Coordenadoria de Aperfeiçoamento do Ensino Superior, Brasília, DF, Brazil); name: CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico, Brasília, DF, Brazil); DOI: 10.13039/100000738, name: Department of Veterans Affairs (USA); DOI: 10.13039/100000002, name: NIH (National Institutes of Health, award: HL14388
- Language
- English
- Date published
- 02/2014
- Academic Unit
- Molecular Physiology and Biophysics; Cardiovascular Medicine; Fraternal Order of Eagles Diabetes Research Center; Internal Medicine
- Record Identifier
- 9984025595402771
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