The reversibility of sperm quality after discontinuing nandrolone decanoate in adult male rats

Aim： To investigate the reversibility of the effect of nandrolone decanoate （ND） on sperm parameters after discontinuing the drug. Methods： Three groups of rats received peanut oil （control）, low and high doses of ND for 14 weeks, respectively. Each group was divided into subgroups A and B, in which rats were killed 14 and 28 weeks after initiating the injection, respectively. Results： Sperm count and motile sperm fraction were decreased in the subgroups A and B that received low and high doses of ND in comparison with the controls A and B, respectively. The sperm count and motile sperm fraction increased in the subgroups B that received low and high doses of ND in comparison with their corresponding subgroups A. The number of normal morphology sperm was decreased significantly in subgroups A receiving low and high doses of ND in comparison with the control subgroup A. However, this parameter was not decreased in subgroups B receiving low and high doses in comparison with the control subgroup B. The normal sperm morphology did not show any significant differences in the subgroups B in comparison with their corresponding subgroups A. Conclusion： The 14-week injection of low and high doses of ND decreases sperm quality and quantity in rats. These parameters were improved after discontinuing ND, but not recovered completely even when they are left untreated for 14 weeks.

Differences of Matrix Metalloproteinase 2 Expression between Left and Right Ventricles in Response to Nandrolone Decanoate and/or Swimming Training in Mice

Background： Matrix metalloproteinase （MMP）-2 plays an important role in the remodeling of left ventricles （LVs） and right ventricles （RVs）. We investigated the differences of MMP-2 expression between LV and RV in response to nandrolone dccanoate （ND）, swimming training （ST）, and combined ND and ST （NS） in mice, based on their structural, functional, and biochemical characteristics. Methods： Totally 28 male C57B1 mice （6 weeks old; 20-23 g） were divided into four groups, including the control （n = 7）, ND （n = 6）, ST （n = 8）, and NS （n = 7） groups. After respective treatments for 8 weeks, echocardiographic examination was used to assess the cardiac structure and function. Van Gieson stain was used to examine the fibrosis of LV and RV in response to different treatments, and Western blotting analysis was performed to explore different MMP-2 expressions between LV and RV in response to ND and/or ST. Analysis of variance was used for comparing the four groups. Results： At 8 weeks, right ventricular dimension/body weight in the ND group was larger than the other three groups （F = 7.12, P 〈 0.05） according to the echocardiographic examination. Fibrosis induced by ND administration was increased more in RV （2.59%） than that in LV （2.21%）. MMP-2 expression of the ND group in RV was significantly greater than the control and NS groups in RV and the corresponding ND group in LV. Conclusion： The experimental data support the hypothesis that ND administration induces greater MMP-2 expression increase in RV compared to LV, leading to consequent RV dilation.