Evaluation of EnkephalinDegrading Enzymes in Sperm from Heroin-Addicted Men

Background:The aim of this study was to investigate two enkephalindegrading enzymes, aminopeptidase N (APN/ CD13) and endopeptidase (NEP/CD10), gene and protein expression levels in sperm samples of fertile and heroin addicted men, and the correlation between their expressions and semen quality.Materials and MethodsIn this casecontrolled study, semen was collected from 24 normozoospermic healthy (as a control group) and 24 heroinaddicted men donors (as case or addiction group). Sperm cells isolated by Cook Medical gradient (4080%) and followed up by swimup techniques were used for realtime quantitative polymer ase chain reaction (qPCR) and flow cytometry techniques to assess APN/CD13 and NEP/CD10 genes and proteins subsequently. Semen parameters were analyzed by computerassisted sperm analysis.Results:The findings revealed that there were significant differences in sperm total motility (41.07 ± 3.63 vs. 63.03 ± 3.31 %, P=0.0001), progressive motility (35.21 ± 2.64 vs. 20.93 ± 3.22%, P=0.001) and viability (69.9 ± 4.69 vs. 86.81 ± 1.26 %, P=0.002) in the addicted group vs. control ones. APN and NEP gene expression levels in the addicted group decreased compared with the control ones (1.00 ± 0.67 vs. 0.36 ± 0.13, P= 0.008 and 1.07 ± 0.11 vs. 0.52 ± 0.12 0.002, respectively). Flow cytometry analysis showed that the average percent of APN/CD13 in heroin consumers significantly decreased compared with the healthy ones, while NEP/CD10 rate between two groups was similar. We also observed that duration of drug dependence is correlated with sperm viability (r=0.627, P=0.016) and motility (r=0.410, P=0.05), NEP (r=0.434, P= 0.049), and APN (r=0.641, P=0.002) gene expression levels.Conclusion:We conclude that semen quality and enkephalindegrading enzymes were altered in heroinaddicted men. other confirming the internal validity of our estimates.