Figure 4: Plasma renin activity (PRA) (A) and plasma aldosterone concentration (PA) (B) in control dogs, and dogs with RF, CHF and CHF and RF in combination. *P<0.05 vs. control, **P<0.01 vs. control, +P<0.05 vs. RF, ++P<0.01 vs. RF, and P<0.05 vs. CHF. There were 5 dogs in each group.