Preischemic efferent vagal stimulation increases the size of myocardial infarction in rabbits. Role of the sympathetic nervous system.

BUCHHOLZ B; DONATO M; PEREZ V; IVALDE FC; HÖCHT C; BUITRAGO E; RODRIGUEZ M; GELPI RJ

INTERNATIONAL JOURNAL OF CARDIOLOGY

ELSEVIER IRELAND LTD

Lugar: Amsterdam; Año: 2012 vol. 155 p. 490 - 491

0167-5273

ABSTRACT Background: Exogenously administered acetylcholine activates ischemic preconditioning, whereas prolonged vagal nerve stimulation (VNS) reduces mortality secondary to chronic heart failure. However, with respect to the effects of VNS applied before ischemia, there are no conclusive data on myocardial infarction in vivo. The aim of this work was to evaluate the effects of preischemic VNS on acute myocardial infarction in rabbits. Methods: Coronary artery was ligated for 45 min followed by 4 h of reperfusion (Group 1, control; n=14). Group 2 (n=9) received the same protocol as Group 1, except that, before ischemia, it received right efferent VNS for 10 min followed by 5 min of recovery. Group 3 (n=5) received the same protocol as Group 2, but atropine was administered during VNS. Group 4 (n=6) received the same protocol as Group 2, but atenolol, a β1-adrenergic blocker, was administered. Group 5 (n=4) received atenolol during ischemia and reperfusion, but VNS was not performed. Group 6 (n=5) received the same protocol as group 2 but reserpine was administered 24 hs before VNS. Group 7 (n=4) received reserpine, but VNS was not performed. Results: Preischemic VNS increased the infarct size from 45.2 ± 2.4 in group 1 to 62.9 ± 3.1% in group 2 (p