Sarcoplasmic reticular and myofibrillar activities in PO-induced cardiac dysfunction in rats with or without CAP and LOS treatments for 8 weeks

ParametersControlPOPO + CAPPO + LOS
A. Cardiac function
LVDP (mmHg)122 ± 2.890 ± 3.1*114 ± 2.5112 ± 2.5
LVEDP (mmHg)3.6 ± 1.010.8 ± 2.1*4.5 ± 0.65.7 ± 0.4
B. SR activity and protein and gene expression
Ca2+-uptake (nmol Ca2+/mg per min)80.0 ± 3.646.7 ± 1.8*70.7 ± 1.867.0 ± 3.7
Ca2+-release (nmol Ca2+/mg per min)20.5 ± 1.913.0 ± 0.9*18.2 ± 0.917.2 ± 0.9
Ca2+-stimulated ATPase protein content (% of control)10080.0 ± 0.4*94.0 ± 2.092.06 ± 3.0
Ca2+-stimulated ATPase mRNA levels (% of control)10056.0 ± 2.0*88.0 ± 3.086.0 ± 3.0
C. MF and myosin activities
MF Ca2+-stimulated ATPase (μmol Pi/mg per h)11.5 ± 0.85.9 ± 0.02*10.1 ± 0.889. 81 ± 0.22
Myosin Ca2+-ATPase (μmol Pi/mg per h) Myosin mRNA levels (Relative intensity)18.8 ± 0.512.7 ± 0.02*17.4 ± 0.516.9 ± 0.5
α-MHC0.28 ± 0.020.13 ± 0.03*0.23 ± 0.020.22 ± 0.01
β-MHC0.03 ± 0.011.18 ± 0.10*0.08 ± 0.010.10 ± 0.02

Values are mean ± SE of 6 animals in each group. CAP: captopril (2 g/L); PO: pressure overload; LVDP: left ventricular developed pressure. Data are based on the analysis of the information in Figures 1, 3, 4, 5 and 6 in our paper Liu et al. Clin Exp Hypertens. 1999;21:145–56 [153]. *P < 0.05 compared with control; P < 0.05 compared with PO group