Effect of Valsartan on Sarcoplasmic Reticulum Ca2+-ATPase Pump of the Left Ventricular Myocardium in Rats with Heart Failure with Preserved Ejection Fraction

OBJECTIVES: The aim was to investigate the effects of valsartan on the sarcoplasmic reticulum Ca(2+)-ATPase pump (SERCA) and L-type Ca(2+) channel current (I_CaL) of the left ventricular myocardium in rats with heart failure with preserved ejection fraction. METHODS: The 30-week-old male spontaneously hypertensive rats (SHRs) are randomly divided into the non-Valsartan and Valsartan groups, and the 30-week-old male Wistar-Kyoto rats served as control rats. The expression of SERCA is measured by Western blot. The I_CaL is measured by whole-cell patch clamp. The left ventricular end-diastolic pressure and left ventricular relaxation time constant quantity are measured at the same time. RESULTS: The left ventricular end-diastolic pressure is much higher in SHRs compared with that in control rats (p < 0.01). The left ventricular relaxation time constant quantity is markedly extended in SHRs compared with control rats (p < 0.01). Valsartan cannot increase the expression of SERCA nor decrease the density of I_CaL compared with the non-Valsartan group (p > 0.05). CONCLUSIONS: Valsartan has no effect on SERCA and I_CaL of the left ventricular myocardium in rats with heart failure with preserved ejection fraction.