Heart Reaction to Nandrolone Decanoate plus Two Different Intensities of Endurance Exercise: Electrocardiography and Stereological Approach

Regarding the negative effects of androgenic anabolic steroids (AASs) abuse, the long-term effect of nandrolone decanoate with/without two intensities of endurance exercise training was investigated on heart tissue and electrocardiogram (ECG) in rats. The experiment was conducted on 63 male Wistar rats, which were 4 months old. The rats were divide into groups of control (CTL), arachis oilasnandrolone solvent (Ar), nandrolone (Nan) (received a dose of 5 mg/kg twice/week for 8 weeks), mild swimming exercise training (mEx), severe exercise (sEx), sEx + Nan, mEx + Nan, mEx + Ar, and sEx + Ar. During the 8 weeks of swimming exercise, the animals carried dumbbells equivalent to 2% of their body weight, which was gradually increased and reached 5% and 8% in the 6th week for mild and severe exercises, respectively. Finally, ECGs recording and samplings were done. Both types of exercise, without nandrolone, significantly reduced the heart rate and increased the RR interval of ECG. Nandrolone alone and with mild (P < 0.050) and intense exercise (P < 0.010 vs. CTL) increased the left ventricular hypertrophy (LVH) index. Left ventricular volume was significantly higher in the Nan group (P < 0.050) compared to the CTL group and all exercise groups (P < 0.010) compared to the Nan, CTL, and Ar groups. Myocytes volume increased in the presence of both of mild and high-intensity exercise plus nandrolone (P < 0.050 vs. CTL and Ar groups). Hydroxyproline value of the heart was significantly higher in the nandrolone group compared to all other groups (P < 0.001). Exercise prevented the effect of nandrolone on hydroxyproline. Both levels of swimming exercise prevent the effect of nandrolone on the production of hydroxyproline and fibrotic cardiac remodeling.