Increased Na+ /Ca2+ Exchanger Expression/Activity Constitutes a Point of Inflection in the Progression to Heart Failure of Hypertensive Rats

JESICA SOLEDAD RODRIGUEZ ; JORGE OMAR VELEZ RUEDA ; MARGARITA ANA SALAS; ROMINA BECERRA ; MARIANO NAHUEL DI CARLO; MATILDE SAID; LETICIA VITTONE; GUSTAVO RINALDI; ENRIQUE L PORTIANSKY; CECILIA MUNDIÑA-WEILENMANN ; JULIETA PALOMEQUE ; ALICIA MATTIAZZI

PLOS ONE

PUBLIC LIBRARY SCIENCE

Lugar: San Francisco; Año: 2014 vol. 29 p. 1 - 10

1932-6203

Spontaneously hypertensive rat (SHR) constitutes a genetic model widely used to study the natural evolution of hypertensive heart disease. Ca²⁺-handling alterations are known to occur in SHR. However, the putative modifications of Ca²⁺-handling proteins during the progression to heart failure (HF) are not well established. Moreover, the role of apoptosis in SHR is controversial. We investigated intracellular Ca²⁺, Ca²⁺-handling proteins and apoptosis in SHR vs. control Wistar rats (W) from 3 to 15 months (mo). Changes associated with the transition to HF (i.e. lung edema and decrease in midwall fractional shortening), occurred at 15 mo in 38% of SHR (SHRF). In SHRF, twitch and caffeine-induced Ca²⁺ transients, significantly decreased relative to 6/9 mo and 15 mo without HF signs. This decrease occurred in association with a decrease in the time constant of caffeine-Ca²⁺ transient decay and an increase in Na⁺/Ca²⁺ exchanger (NCX) abundance (p