Premium
Parasympathetic Prejunctional Inhibition of Cardiac Sympathetic Nerves is Reduced in a Rodent Model of Heart Failure.
Author(s) -
Donohue Timothy J,
Smith Peter G
Publication year - 2009
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.23.1_supplement.789.6
Subject(s) - medicine , heart rate , dobutamine , stimulation , heart failure , cardiology , vagal tone , sympathetic nervous system , vagus nerve , endocrinology , anesthesia , autonomic nervous system , blood pressure , hemodynamics
Parasympathetic prejunctional inhibition is an important mechanism regulating cardiac sympathetic tone. This study examined whether axo‐axonal 'uncoupling' contributes to reduced vagal tone in heart failure. Adult male rats underwent left coronary artery ligation; at 12‐16 weeks, ventricular ejection fraction and mean arterial pressure were reduced, consistent with heart failure. To assess prejunctional inhibition, cardiac slowing in response to right vagal nerve stimulation was compared when basal heart rate was elevated to comparable levels by β1 agonist dobutamine administration or electrical stimulation of cardiac sympathetic innervation. In sham‐ligated rats, vagal stimulation reduced heart rate to a greater degree during sympathetic stimulation than during dobutamine administration (ratio of 1.2 + 0.07at 8Hz). However, following infarct, vagal stimulation was less effective in reducing sympathetic‐ vs. dobutamine‐induced tachycardia (0.83 + 0.07 , p<0.001). These data support the conclusion that vagal prejunctional inhibition of sympathetic nerves is reduced in a rodent model of heart failure. NIH grant HL079652