Effects of different doses of ethanol on sperm parameters, chromatin structure and apoptosis in adult mice

Chronic ethanol abuse causes reproductive organ failure and infertility in both humans and laboratory animals. Since sperm has a critical role in reproductive function, the objective of this unique study was to evaluate the effects of different doses of ethanol on sperm parameters, chromatin structure and apoptosis in adult mice.A total of 36 adult male mice were equally divided into four groups. Group 1 received ethanol (10%, v/v) containing saccharin (0.2%, w/v), group 2 received ethanol (5%, v/v) containing saccharin (0.1%, w/v), group 3 was treated with saccharin (0.2%, w/v) and group 4 served as control and fed on basal diet for 35 days. Finally, the left cauda epididymis of each animal was cut and placed in Ham's F10 medium. Retrieved spermatozoa were used to analyze count, motility, morphology and viability. Sperm chromatin condensation and DNA integrity were assessed by five different tests including chromomycin A3 (CMA3), toluidine blue (TB), sodium dodecyl sulfate (SDS), and SCD (sperm chromatin dispersion) and sperm apoptosis was assessed by TUNEL.Following ethanol consumption, the sperm count diminished in the ethanol-treated groups. A decrease in sperm motility and an increase in the rate of morphological abnormalities (coiled and broken tails) were seen in the experimental and saccharin groups in comparison with controls. We showed that ethanol consumption can disturb sperm DNA integrity and chromatin remodeling and it may also induce sperm apoptosis. The rates of sperm apoptosis were 51.57 ± 7.45 and 42.85 ± 6.76 in the high ethanol dose and low ethanol dose groups, respectively.The results showed that alcohol has negative effects on sperm parameters, chromatin/DNA integrity and apoptosis in mice. These alcohol-induced sperm anomalies may be dose-dependent.