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

Background: 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. methods: 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. findings: 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. conclusion: both levels of swimming exercise prevent the effect of nandrolone on the production of hydroxyproline and fibrotic cardiac remodeling.