Ferreira-Melo SE, Demacq C, Lacchini S, Krieger JE, Irigoyen MC, Moreno H. Sildenafil preserves diastolic relaxation after reduction by L-NAME and increases phosphodiesterase-5 in the intercalated discs of cardiac myocytes and arterioles . Clinics. 2011;66(7):1253-1258. doi:10.1590/S1807-59322011000700022