Effect of High Light Level on Sperm parameters in Mice

Background and aims: High light level of natural or artificial sources in some workplaces may be considered as a hazardous physical agent. The present study aimed to assess the effect of light level of 1000 lux on sperm parameters  in mice.   Methods: The subjects were assessed in two group including 1. Exposed (n= 6; exposed to light level of 1000 lux during 5 eight-hour days), 2. Unexposed or control (n= 6; similar condition, but without exposure). At the end of the exposure scenario, first they were anesthetized intramuscularly with ketamine and xylazine, then Testicular Extract was done and to study spermogram, samples which were putted in culture medium. Finally, Paraffin molds and 5-micron slices were provided and all tests related to tissue index were performed on the samples. The mean three-time intra-group replication of the data with a significant level of 0.05 was reported. Data were analyzed by one-way ANOVA and Tukey's post hoc tests.   Results: There was a significant difference in total sperm motility between two groups (exposed: 60.7% ± 0.96; control: 72.4 %± 1.02), percentage of sperms with normal morphology (exposed: 45.5 ± 3.85; control: 73.35 ± 1.6), percentage of survival of sperm (exposed: 58.68 ± 1.44; control: 74.36 ± 1.65), and internal diameter of the spermatozoa tubes (exposed: 97.11 μm ± 1.79; control: 66.82 μm ± 1.22) (P <0.05). No significant difference in the number of sperm in millions (exposed: 11.11 ± 1.11; control: 4.51 ± 0.09) and external diameter of the spermatozoa tubes (exposed: 160.27 μm ± 1.95; control: 161.89 ± 1.33 μm) was observed between the two groups (P> 0.05).   Conclusion: According to our findings, exposure to the light level of 1000 lux may reduce total motility, natural morphology percentage and survival rate of sperms, which is expected to increase with the possibility of different degrees of infertility with male factor over time. There was also an increase in the internal diameter of the sperm membranes due to the exposure to 1000 lux, indicating cell differentiation and death in a large number of different germ cells.