Investigation of the time-dependent molecular mechanisms progression and structural changes in experimentally created ischemia and reperfusion model in the ovarian tissues of female rats

The aim of this study is to investigate severity of ischemia and reperfusion injury, it's connection with inflammatory cytokines and time dependent changes of reperfusion in the detorsioned rat ovary created after ovarian torsion by using histopathological, biochemical, electron-microscopic metods at the molecular level. Material and Method: 12-week-old 78 Wistar-Albino female rats were used in this study. A total of rats were divided into 13 groups which consist of 6 rats. Experimental groups consists of sham, ischemia(I) and ischemia/reperfusion(I/R) groups. İschemia groups consists of 30-min(I/30), 60-min(I/60), 90-min(I/90), 120-min(I/120), 150-min(I/150), 180-min(I/180) groups due to ischemia periods. In ischemia/reperfusion groups all animals underwent reperfusion respectively for 30-min(IR/30), 60-min(IR/60), 90-min(IR/90), 120-min(IR/120), 150-min(IR/150), 180-min. (IR/180), after 180-minute ischemia. Obtained ovarian tissues were evaluated by light-microscopy, electron-microscopy, biochemical and molecular methods at the end of the experiment. Results: Light-microscopic evaluation of I/90, I/180, IR/60 and IR/90 groups revealed an intensive vascular congestion and hemorrhage in ovarian tissues. İmmunohistochemical assessment indicated severe immunreactivity in I/180, IR/60 and IR/90 groups. IL-1b,IL-6,TNF-α,NF-κB and iNOS expression significantly increased compared to the control group in I/180,IR/30,IR/60 groups, while eNOS expression significantly decreased in I/120,I/150,I/180 groups. Various basement membrane changes detected in I/120 and IR/150 groups, also changes of endothelial-cells detected in I/150 ve IR/90 groups by ultrastructural-examination. Conclusion: The results of our study revealed that the ovarian tissue significantly affected from the ischemia and reperfusion. Tissue damage strongly increased especially in I/90,I/120,I/150,I/180 groups according to the duration of ischemia, while in IR/180, IR/150 ve IR/120 groups it was severely decreased when compared to other groups.