Effects Of Lasted Low Flow Reperfusion Postconditioning On Incomplete Testicular Torsion Ischemia-reperfusion Injury In Rabbit

Objective: Explore the protective effects、relevant mechanisms and ultrasonographyappearances of lasted low flow reperfusion postconditioning with different time andmethods on incomplete testicular torsion ischemia-reperfusion injury (IRI) in rabbit.Methods:70male rabbits were randomly divided into mild ischemia group(A) andmoderate ischemia group (B), each group was divided into control groups (SA、SB,3rabbits each group) and ischemia postconditioning groups (A1-4、B1-4,8rabbits eachgroup). Choosed one side testis randomly and hypodesmused the spermatic cord tomake the color doppler flow signals down to50%, then checked every hour, by5-9hours, the mild testicular ischemia models were got when the color doppler flowsignals down to20%-30%.Extended the time to10-15hours, the moderate testicularischemia models were got when the color doppler flow signals down to5%-10%. Thecontrol groups got reperfusion completely and immediately. The ischemiapostconditioning groups were divided into1-4groups according to time and methods.Groups1(A1、B1) got same lasted low flow reperfusion postconditioning with45s,groups2(A2、 B2) got lasted gradually increasing low flow reperfusionpostconditioning with45s, groups3(A3、B3) got same lasted low flow reperfusionpostconditioning with30s, groups4(A4、B4) got lasted gradually increasing low flowreperfusion postconditioning with30s. After3days of breeding, the histologystructure, tissue sample of SOD and MDA were determined. The expression of Bax、caspase-3and HIF-1α were detected by western blot. The Johnsen’s score、AI wereanalyzed. The gray-scale, color Doppler and CEUS appearances of the preoperation、before reperfusion and postoperation were observed and analyzed.Results: There was no difference between preoperative testicular sizes andpostoperation(p>0.05); the postoperative sizes of groups B1、B2were smaller thanpreoperation(p<0.05), while the postoperative sizes of groups B3、 B4had nochange(p>0.05).In groups A, the Johnsen’s score of group A4was highest, thecontrast of score showed difference with other groups(p<0.05). In groups B, the Johnsen’s score of postconditioning groups were higher than group SB(p<0.05), whilethe score of groups B2、B3were higher than groups B1、B2(p<0.05)，but there wereno difference between groups B1and B2、B3and B4(p>0.05). The SOD vitality werehighest in groups A4and B4, the contrast showed significant difference betweengroup A4and groups SA、A1、A2、A3，group B4and groups SB、B1、B2、B3(p<0.01).The MDA of group A4was lowest in groups A，the contrast showed difference withgroups SA、A1、A2(p<0.05), but there were no difference in groups B by multiplecomparsion (p=0.257).The expression of caspase-3and AI was lowest in groups A4and B4, while their HIF-1α were maximum,which had difference with relevantcontrol groups (p<0.05). The Bax relative content of group A4was significantly lowerthan other groups(p=0.000) in groups A，the content of postconditioning groups ingroups B were significantly lower than group SB(p=0.000)，but there were nodifference in postconditioning groups of B. Analyzed the CEUS of preoperation、before reperfusion and postoperation, the contrast of preoperative parameters showedno difference in groups(p>0.05). Compared the parameters of preoperative and beforereperfusion in groups A and B, AT、TTP、DT/2were significantly elevated(p=0.000),PI、PBD were significantly lower (p=0.000).Compared the postoperative parameterswith preoperation in groups A, the AT、TTP had no change(p>0.05), the PI、PBD ingroups SA、A1、A2、A3were reduced than preoperation(p<0.05) while the PI、PBDin group A4had no change with preoperation(p>0.05), and the DT/2of groups A2、A3、A4were significantly shorten than preoperation(p<0.01) while the DT/2ofgroups SA、A1had no change with preoperation(p>0.05). In groups B, theAT、TTP ofgroups SB、B1were elevated than preoperation (p<0.05) while the groups B2、B3、B4had no change(p>0.05)，the PI、PBD of groups SB、B1、B2、B3were lower thanpreoperation(p<0.05) while the group B4had no change(p>0.05)，the DT/2of groupSBwas elevated(p=0.013) while the groups B1、B2、B3had no change(p>0.05)，thegroup B4was shorten than preoperation(p=0.003).Conclusions:①The gray-scale, color Doppler and CEUS offer the basis for thediagnosis of testicular torsion and function resume;②The protective effects of lastedlow flow reperfusion postconditioning has relation to the time of reperfusion and the bloodflow growth, the lasted gradually increasing low flow reperfusionpostconditioning with30s increase the bloodflow to50%，then gives completelyreperfusion，it is the beast critical point for completely reperfusion；③The lasted lowflow reperfusion postconditioning acts on the core link of IRI, balances the produceand eliminate of ROS, restrains the cell apoptosis, guides the intrinsic HIF-1αincreasing by low oxygen and enhances the adaptation when ischemia and hypoxia.