Arrhythmogenic effect of androgens on the rat heart

ARGENZIANO M.; TISCORNIA G.; MORETTA R.; CASAL L.; POTILINSKI M.; AMORENA C.; GARCÍA-GRAS E.

JOURNAL OF PHYSIOLOGICAL SCIENCES

SPRINGER TOKYO

Lugar: Tokyo; Año: 2017 vol. 67 p. 217 - 225

1880-6546

In most species androgens shorten the cardiacaction potential and reduce the risk of afterdepolarizations.Despite the central role of the rat model in physiologicalstudies, the effects of androgens on the rat heart are stillinconclusive. We therefore performed electrophysiologicalstudies on the perfused rat right ventricular free wall. Wefound a correlation between androgenic activity and apropensity to generate ventricular ectopic action potentials.We also found that the testosterone treatment increasedaction potential duration at 90 % of repolarization(APD90), while androgenic inhibition increased the time topeak and decreased APD90. We observed that the voltagegatedpotassium channel Kv4.3 and the bi-directionalmembrane ion transporter NCX in the rat myocardiumwere regulated by androgenic hormones. One possibleexplanation for these findings is that due to the expressionof specific ion channels in the rat myocardium, the actionpotential response to its hormonal background is differentfrom those described in other experimental models. Ourresults indicate that androgenic control of NCX expressionplays a key role in determining arrhythmogenicity in the ratheart