当前位置： SCI文献检索 > CLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY期刊下所有文献 > Increased cardiac sympathetic drive and reduced vagal modulation following endothelin receptor antagonism in healthy conscious rats.

Increased cardiac sympathetic drive and reduced vagal modulation following endothelin receptor antagonism in healthy conscious rats.

Abstract：

:1. The present study evaluated changes in autonomic control of the cardiovascular system in conscious rats following blockade of endothelin (ET) receptors with bosentan. 2. Rats were treated with bosentan or vehicle (5% gum arabic) for 7 days by gavage. 3. Baseline heart rate (HR) was higher in the bosentan-treated group compared with the control group (418 +/- 5 vs 357 +/- 4 b.p.m., respectively; P < 0.001). This baseline tachycardia was associated with a lower baroreflex sensitivity of the bradycardiac and tachycardiac responses in the bosentan-treated group compared with the control group. Sequential blockade of the parasympathetic and sympathetic autonomic nervous system with methylatropine and propranolol showed a higher intrinsic HR in the bosentan-treated group compared with the control group (411 +/- 5 vs 381 +/- 4 b.p.m., respectively; P < 0.05). This was accompanied by a higher cardiac sympathetic tone (31 +/- 1 vs 13 +/- 1%, respectively; P < 0.01) and a lower vagal parasympathetic tone (69 +/- 2 vs 87 +/- 2%, respectively; P < 0.01) in the bosentan-treated group compared with the control group. Variance and high-frequency oscillations of pulse interval (PI) variability in absolute and normalized units were lower in the bosentan-treated group than in the control group. Conversely, low-frequency (LF) oscillations of PI variability in absolute and normalized units, as well as variance and LF oscillations of systolic arterial pressure variability, were greater in the bosentan-treated group than the control group. 4. Overall, the data indicate an increased cardiac sympathetic drive, as well as lower vagal parasympathetic activity and baroreflex sensitivity, in conscious rats after chronic blockade of ET receptors with bosentan.

journal_name

Clin Exp Pharmacol Physiol

journal_title

Clinical and experimental pharmacology & physiology

authors

Souza HC,Terzini GC,da Silva VJ,Martins-Pinge MC,Salgado HC,Salgado MC

doi

10.1111/j.1440-1681.2008.04866.x

subject

Has Abstract

pub_date

2008-07-01 00:00:00

pages

751-6

issue

eissn

0305-1870

issn

1440-1681

pii

CEP4866

journal_volume

pub_type

杂志文章

在线工具

Increased cardiac sympathetic drive and reduced vagal modulation following endothelin receptor antagonism in healthy conscious rats.