First and second window of protection of pre-ischemic vagal stimulation on myocardial infarction in mice

MÉNDEZ DIODATI N; CASANOVA V; BERNATENÉ E; BUCHHOLZ B; KELLY J; FRANCO RIVEROS V; , GELPI RJ

Buenos Aires

Congreso; LXII Reunión Anual de la Sociedad Argentina de Investigación Clínica (SAIC); 2017

We have previouslyproven that vagal stimulation (VS) decreases infarct size (IS) when appliedbefore ischemia, thus mimicking classic preconditioning. Our objective was tostudy the chronology and mechanisms of the protective effect of VS, and toassess whether the protection is comprised of a first and second window. Micewere randomly assigned to different protocols (n=5-7 per group). The control grouphad 30 min of regional myocardial ischemia and 2 h of reperfusion (I/R). Theother groups consisted of 10 min of pre-ischemic VS (pVS) and different timesof recovery between VS and I/R protocol: 5 min, 3-6-12-24-48-72-96 h. The 5 min,3 h and 72 h groups were redone to administer a muscarinic receptor inhibitor(atropine). pVS-5min and pVS-72h were given a mitochondrial K+ ATP channelblocker (5-HD) and a nitric oxide synthase inhibitor (L-NAME). All animals werecatheterized to measure ventricular function. Hearts were dyed with Evans Blue andincubated in TTC to measure IS. pVS-5min had smaller IS in comparison to I/R(44±3% and 57±2%, respectively; p