NPPA and cardiac hypertrophy: Adult mouse cardiomyocytes were treated with angiotensin II (Ang II) and transfected with Mhrt; cardiac hypertrophy was evaluated by estimating atrial natriuretic peptide, brain natriuretic peptide, and beta-myosin heavy-chain levels, and cell surface area by reverse transcription-quantitative polymerase chain reaction, western blotting, and immunofluorescence staining.