Vagal Stimulation Mimics Preconditioning and Postconditioning of Ischemic Myocardium in Mice by Activating Differente Protection Mechanisms.

BUCHHOLZ B; KELLY J; MUÑOZ M; BERNATENÉ, EA.; MÉNDEZ DIODATI N; GONZÁLEZ MAGLIO D; DOMINICI FP; GELPI RJ

AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY

AMER PHYSIOLOGICAL SOC

Lugar: Bethesda; Año: 2018 p. 1289 - 1297

0363-6135

Buchholz B, Kelly J, Muñoz M, Bernatené EA, Méndez DiodatiN, González Maglio DH, Dominici FP, Gelpi RJ. Vagal stimulationmimics preconditioning and postconditioning of ischemic myocardium in mice by activating different protection mechanisms. Am JPhysiol Heart Circ Physiol 314: H1289 ?H1297, 2018. First publishedApril 6, 2018; doi:10.1152/ajpheart.00286.2017.?Vagal stimulation(VS) during myocardial ischemia and reperfusion has beneficial effects. However, it is not known whether short-term VS applied before ischemia or at the onset of reperfusion protects the ischemic myocardium. This study was designed to determine whether shortterm VS applied before ischemia or at the onset of reperfusion reducesmyocardial infarct size (IS), mimicking classic preconditioning and postconditioning. A second objective was to study the participation of muscarinic and nicotinic receptors in the protection of both preischemic and reperfusion stimulation. FVB mice were subjected to 30 min of regional myocardial ischemia followed by 2 h of reperfusion without VS, with 10-min preischemic VS (pVS), or with VS during the first 10 min of reperfusion (rVS). pVS reduced IS, and this effect was abolished by atropine and wortmannin. rVS also reduced IS in asimilar manner, and this effect was abolished by the 7-nicotinicacetylcholine receptor blocker methyllycaconitine. pVS increased Aktand glycogen synthase kinase (GSK)-3 phosphorylation. No changes in Akt and GSK-3 phosphorylation were observed in rVS. Stimulation-mediated IS protection was abolished with the JAK2 blockerAG490. rVS did not modify IL-6 and IL-10 levels in the plasma or myocardium. Splenic denervation and splenectomy did not abolish the protective effect of rVS. In conclusion, pVS and rVS reduced IS by different mechanisms: pVS activated the Akt/GSK-3 muscarinic pathway, whereas rVS activated 7-nicotinic acetylcholine receptors and JAK2, independently of the cholinergic anti-inflammatory pathway.