Cardioprotective role of igf-1 in the hypertrophied myocardium of the spontaneously hypertensive rats: a key effect on nhe-1 activity

YEVES, ALEJANDRA M.; BURGOS, JUAN I.; MEDINA, ANDRÉS J.; VILLA-ABRILLE, M. CELESTE; ENNIS, IRENE L.

ACTA PHYSIOLOGICA

WILEY-BLACKWELL PUBLISHING, INC

Año: 2018

1748-1708

Aim: Myocardial Na+ /H+ exchanger-1 (NHE-1) hyperactivity and oxidative stress are interrelated phenomena playing pivotal roles in the development of pathological cardiac hypertrophy and heart failure. Exercise training is effective to convert pathological into physiological hypertrophy in the spontaneously hypertensive rats (SHR) and IGF-1 ?key humoral mediator of exercise training- inhibits myocardial NHE-1, at least in normotensive rats. Therefore, we hypothesize that IGF-1 by hampering NHE-1 hyperactivity and oxidative stress should exert a cardioprotective effect in the SHR. Methods: NHE-1 activity [proton efflux (JH + ) mmol L min-1], expression and phosphorylation; H2O2 production; superoxide dismutase (SOD) activity; contractility and calcium transients were measured in SHR hearts in the presence/absence of IGF-1. Results: IGF-1 significantly decreased NHE-1 activity (JH + at pHi 6.95: 1.39±0.32, n=9 vs. C 3.27±0.3, n=20, p