The Protective Effect Of Ischemic Preconditioning On Parathyroid Ischemia-reperfusion Injury

Objective:To Explore intraoperative parathyroid whether different levels of mechanical ischemia caused by ischemia-reperfusion injury and ischemic preconditioning(ischemic preconditioning,IPC)for parathyroid ischemia-reperfusion injury(ischemia-reperfusion injury,I-RI)has a protective effect,further proved able to ischemia-reperfusion injury of parathyroid protect good pretreatment period,for the protection of the parathyroid gland provide new ideas and methods.Methods:The experimental rabbits were randomly divided into A,B,C(IP0.5min,IPlmin,IP3min,IP5min)and D 7 groups,with 8 in each group.Group A(sham operation group):to expose and probe the thyroid and parathyroid glands:ischemia-reperfusion injury(group B)were randomly divided into the left side of the ischemia group and ischemia-reperfusion injury on the right side,with noninvasive vascular clamp clip left and right sides of the parathyroid gland artery 5 min,10 min,20 min,30 min after the left group remove the parathyroid placed directly on the fixed in 10%formaldehyde solution,the right set of ischemia of the corresponding period of 5 min,10 min,20 min,take out after 30 min reperfusion after 30 min parathyroid placed in 10%formaldehyde solution fixed;Ischemic preconditioning(IP):group C were randomly divided into four groups,which was IP0.5min,IPlmin,IP3min and IP5min.Respectively with noninvasive vascular clamp and clip parathyroid gland artery 0.5 min,1 min,3 min,5 min,respectively to restore blood flow after 0.5 min,1 min,3 min,5 min of ischemic preconditioning,repeated the above 2 times each group of ischemia reperfusion after 30 min after 30 min.D(RI of ischemia reperfusion group):exposed thyroid and parathyroid glands,and closed the parathyroid artery directly with the non-invasive vessel clamp,and then perfusion for 30min after 30min of ischemia.A,C,D group in postoperative 1,7,14,30 D for parathyroid tissue of rabbit placed in 10%formaldehyde solution,group B in the implementation of ischemia and reperfusion after the intervention,immediately remove the parathyroid placed in 10%formaldehyde solution.The survival and pathological changes of parathyroid glands were observed by using HE staining,and the apoptosis of parathyroid cells was detected by TUNEL method.Results:1.Morphology of parathyroid glands:after the corresponding time period of the parathyroid artery of the rabbit,the surface color of the parathyroid gland changes from bright red to pale.2.Pathological results:group A(sham operation group):normal parathyroid tissue,mainly dominated by main cells,without obvious bleeding and cell necrosis;Group B(ischemia reperfusion injury group):the left ischemic group showed blood vessel dilation and hyperemia,bleeding area of 20-30%.The right ischemia reperfusion injury group was characterized by extensive hemorrhage and local necrosis.The hemorrhage area of the right parathyroid group was 40%,and the necrotic area was 5%.Group C(ischemic pretreatment group IP):IP0.5min and IPlmin group of parathyroid glands were found to be hyperemic and dilated,without obvious necrosis;The IP3min group showed hemorrhage and congestion in the parathyroid glands.The IP5min group showed hemorrhage and necrosis in the parathyroid glands,with a necrotic area of 20%and residual cell proliferation.D group(RI)of ischemia reperfusion group:extensive hemorrhage of parathyroid glands,thrombosis,necrotic area of 4%-20%,partial cell vacuolation,and a small amount of fibrotic hyperplasia.3.Cell apoptosis in situ end labeling technique(TUNEL method)to detect apoptosis of parathyroid cells:Analysis:statistical cross comparison between the experimental group,the group B parathyroid gland cell apoptosis number can be seen,in a different time,ischemia reperfusion group parathyroid apoptotic cells were significantly higher than those of ischemia group(P<0.05);Of group A,C,D statistical analysis of experimental results in ischemic preconditioning group C group besides IP5min group,the apoptotic cells in the rest of the group were significantly lower than that of group D ischemia-reperfusion group(P<0.05);In group C cross contrast between ischemic preconditioning group,in addition to IP0.5 min,IPlmin IPlmin group and IP3min group(P>0.05),no statistical difference,the rest of the contrast group(P<0.05),the difference was statistically significant.Conclusion:1.Rabbit parathyroid gland under different mechanical ischemia time will cause the corresponding degree of ischemia-reperfusion injury,by ischemia-reperfusion injury of parathyroid ischemia parathyroid gland apoptosis of apoptotic cells.2.Ischemic preconditioning has a certain protective effect on the ischemia reperfusion injury of the parathyroid of the rabbit,in which the ischemic pretreatment time is 0.5min and lmin is a superior pretreatment time.