Circadian Clock on Ionizing Radiation-Induced Testicular Injury

Objective: This research focuses on the interaction between the circadian clock and the damage caused to testicular tissue by x-ray ionizing radiation. By examining the links between circadian rhythms and radiation -induced testicular damage, a deeper understanding of the underlying mechanisms may emerge, potentially leading to new strategies to mitigate or prevent such damage and its subsequent consequences. Methods: Twenty-four Sprague-Dawley rats were divided into 3 groups. Rats in group 1 (control group) did not undergo any procedures. Rats in group 2 (day) received 6 Gy total body external x-ray radiation in a single fraction between the hours 05:00 and 06:00. Rats in group 3 (night) received 6 Gy total body external x-ray radiation in a single fraction between the hours 19:00 and 20:00. Results: The day group was compared with the control group, and a decrease in spermatogenetic cells and edematous areas was observed. In addition, there was vacuolar accumulation in the cytoplasm of spermatids in the germinal epithelium and necrotic Leydig cells in the intertubular spaces. In the night group, we observed that the changes observed in group 2 were significantly restored. In terminal deoxynucleotide transferase dUTP nick end labeling and 8-hyd roxy-2'-de oxygu anosi ne immunohistochemical analyses, we observed significantly increased immunopositivity in group 2 compared to the control group and group 3. Conclusion: In conclusion, it reveals that the circadian clock protects against testicular damage caused by x-ray ionizing radiation. By regulating DNA repair processes, antioxidant defense mechanisms, and other important pathways, the circadian clock appears to increase the resistance of testicular tissues to radiation stress.