Cardiovascular responses elicited by continuous versus intermittent electrical stimulation of the aortic depressor nerve in conscious rats

Author(s)

Brognara, Fernanda ^[1] ; Martins Dias, Daniel P. ^[1] ; Castania, Jaci A. ^[1] ; Fazan, Jr., Rubens ^[1] ; Lewis, Stephen J. ^[2] ; Salgado, Helio C. ^[1]

Affiliation

^[1] Univ Sao Paulo, Ribeirao Preto Med Sch, Dept Physiol, Ave Bandeirantes 3900, BR-14049900 Ribeirao Preto, SP - Brazil

^[2] Case Western Reserve Univ, Sch Med, Dept Pharmacol, Dept Pediat, Div Pulmonol Allergy & Immunol, Cleveland, OH 44106 - USA

• Document type: Journal article
• Source: Life Sciences; v. 148, p. 99-105, MAR 1 2016.
• Web of Science Citations: 1

Abstract

Aims: Short-term (seconds or minutes) continuous electrical activation of the aortic depressor nerve (ADN) in conscious rats has been successfully used to investigate baroafferent function in experimental hypertension, heart failure, and peripheral inflammation. The aimof this studywas to characterize the hemodynamic responses elicited by longer periods (60 min) of continuous or intermittent electrical baroreflex activation. Main methods: Wistar rats were implanted with an electrode around the left ADN and a catheter into a femoral artery. The systolic, diastolic and mean arterial pressure and heart rate were recorded in subjects randomly assigned to continuous or intermittent electrical stimulation. The time-course of cardiovascular responses in conscious rats was examined during longer-term (60 min) continuous (n = 6) or intermittent (5 s ON/3 s OFF; n = 10) electrical stimulation (0.5 mA; 0.25 ms; 30 Hz) of the ADN. Key findings: The prompt (20 s) hypotensive response was greater under continuous stimulation, but no difference was detected in the bradycardic response. The hypotensive response was sustained only by continuous stimulation while no sustained bradycardia was observed in either protocol. Significance: These findings indicate that continuous stimulation of the ADN is more effective in reducing arterial pressure over a longer period (60 min) of stimulation. Nevertheless, both protocols-continuous or intermittent were unable to elicit a sustained bradycardia. (C) 2016 Elsevier Inc. All rights reserved. (AU)

• FAPESP's process: 14/15386-4 - Modulation of the inflammatory response to LPS by electrical activation of the baroreflex in conscious rats
• Grantee: Fernanda Brognara Penteado Dias
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• FAPESP's process: 13/20549-7 - New insights in cardiovascular regulation under physiological and pathophysiological condition
• Grantee: Helio Cesar Salgado
• Support Opportunities: Research Projects - Thematic Grants