Investigation of the effects of tadalafil on the myocardium via electrical and isometric contractions and cardiac markers in Wistar rats

OpenAlex İngilizce

Purpose: Tadalafil, a long-acting phosphodiesterase-5 (PDE-5) inhibitor, is commonly used in the treatment of erectile dysfunction. This study investigates the contribution of tadalafil in cardiac function by measuring isometric and electrical contractions of myocardium in rats. Materials and Methods: Thirty rats were divided into five groups. Basal electrical contractions were recorded via electrocardiogram (ECG) for intervals PR (ms), QRS (ms), QT (ms), Tp (ms), Te (ms), pathological Q and heart beats/min. Then group 1 received saline for 7 days (control); group 2 received tadalafil 1 mg/kg; group 3 received tadalafil 10 mg/kg; group 4 received tadalafil 1 mg/kg for 7 days; group 5 received tadalafil 10 mg/kg for 7 days. After treatments, electrical contractions were re-performed to analyze the differences in ECG. For isometric contractions, hearts were connected to isometric power transducer to determine myocardial contractile forces (g), durations (ms) and frequencies (Hz). Serum samples were collected for cardiac creatine kinase (CK-MB) and cardiac troponin I via ELISA. Results: We found a significant decrease in CK-MB in Group 2 (395.56±124.38 pg/ml) and 3 (377.81±79.61 pg/ml), compared to Group 1 (575.32±83.54 pg/ml). The differences in cardiac contractile forces, contraction durations or frequencies were not statistically significant. Conclusion: Tadalafil did not exert obvious distruption on myocardial electrical or isometrical contractions. It is noteworthy that tadalafil 1 and 10 mg/kg reduced serum CK-MB. Shortening in QT and decrease in heart rate may have important implications on myocardial functions.