Effects Of Ischemic Postconditioning On Testes Ischemia-reperfusion Injury In Rabbits

Objective: To investigate the relationship between the sonographic performances of experi- mentally induced the varying degrees of acute unilateral testicular hemodynamic disorder and following reperfusion and the protective effect of postconditioning treatment of ischemic/reper- fusion(I/R) injury, and to explore its relevant mechanisms.Methods: 42 white male rabbits were randomly divided into groups: sham operation group (group S), ischemia-reperfusion(I/R) group (group A1,B1,C1),ischemia postconditioning (IP) group (group A2,B2,C2),with 6 in each. The acute testicular hemodynamic disorder models were established in all group and were dynamic dynamic observed by color Dppler ultrasound. Before reperfusion ,the ischemic testes in group A1 and A2 showed homogeneous echo and slightly decreased in color Doppler flow signals ,in group B1 and B2 showed heterogeneous echo and obviously decreased in color Doppler flow signals, in group C1 and C2 showed radial or in fragmentis low echo area and color Doppler flow signals disappeared. The ischemic testes in group I/R were reperfusion immediately, the testes in group IP were subjected to 3 episodes of 30 second reperfusion followed by 30 second ischemia.The contrast-enhanced ultrasonogra- phic (CEUS) was performed before operation and reperfusion in each group. The time intensity curves were evaluated by using Syngo US Workplace and the parameters includeβ,time-to- peak(TTP),peak-base indensity(PBD),half of declining time(DT/2) were analyzed. After 3 days of breeding, the CEUS was performed again, the histology structure, tissue sample of malonaldehyde (MDA) and superoxide dismutase (SOD) were determined. The Johnsen's score,apoptosis index(AI) were analyzed. Analysis the correlation between histological,biochemics changes and the gray-scale, color Doppler and CEUS appearances of each groups.Results: The CEUS parameters of bilateral testes showed no significantly difference in all group before operation(p>0.05). Before I/R, the parameters showed no significant difference between group A1 and A2, and no significant difference between group B1 and B2 .The parameters of the ischemic testes is 0 in group C. After reperfusion 3 days, the CEUS parameters showed significant difference between group A and S, and significant difference between group B and S. The content of the MDA showed significant differences between group A1 and A2(p<0.05), group B1 and B2 (p<0.05), but showed no significant difference between group C1 and C2 (p>0.05). The content of the SOD showed significant difference between group A1 and A2(p<0.05), group B1 and B2 (p<0.05), but showed no significant difference between group C1 and C2 (p> 0.05). The Johnsen's score showed significant difference between group A1 and A2 (p<0.05 ), but showed no significant difference between group B1 and B2, group C1 and C2. The apop- tosis index showed significant difference between group A1 and A2 (p<0.05), but showed no significant difference between group B1 and B2, group C1 and C2.The ultrastructure showed significantly different between group A1 and A2, but no significant difference between group B1 and B2, group C1 and C2.Conclusions:①Sonographic appearances of acute testicular hemodynamic disorder is related to histological structure changes after reperfusion.②The IP can activate endogenous protection to reduce the IR injury in the ischemic testes when ischemic injury was not serious.③The IP has a time window, it's different between biochemistry and pathological mechanism, if the testes was damaged seriously, the IP did not work.