Hyperbaric Oxygen Preconditioning Increase Skin Flap Ischemic Tolerance By Modulating Connexin 43 Expression

Objective:It has been proved that hyperbaric oxygen preconditioning can increase skin flap ischemic tolerance,but the molecular mechanisms are unknown.Our study aimed to determine matrix metalloproteinases(MMPs),cell adhesion molecules,NF-κB and other inflammatory factors and analysis the expression of Cx43.By inhibiting Cx43 protein expression research,we clarified hyperbaric oxygen precondition inhibited ischemia and reperfusion inflammatory reaction in Cx43 on inflammatory response regulation mechanism,further proved the hyperbaric oxygen precondition to improve skin flap ischemia tolerance mechanism to promote the survival of the flap.By inhibiting Cx43 protein expression research,we clarified the regulation mechanism of Cx43 to inflammation reaction in hyperbaric oxygen preconditioning inhibiting ischemia and reperfusion inflammation.Methods:Adult male Sprague Dawley rats were divided into five groups.Group 1 was shame surgery group,Group 2 was ischemia/reperfusion(IR)group,Group3、4 and 5 received HBO preconditioning,Group 4 and 5 were wiped with glycerin and Cx43-inhibition in the same dose respectively followed by I/R surgery.Blood perfusion of flap was measured by Laser doppler flowmeters.Hematoxylin and eosin staining was used to observe morphological changes.Protein expression of Cx43 ICAM-1 MMP2 MMP9 NF-κB and VCAM-1 was examined by immunodetection and Western blot.Results:The result of microcirculation analysis showed that the survival and blood perfusion rates increased in the skin flap after HBO exposure,while group Cx43-inhibition increased less significantly than the other two groups.Furthermore,HBO preconditioning increased the expression of Cx43 and inhibited ICAM-1,VCAM-1,MMP-2,MMP-9,and Nuclear Factor kappa B expression as determined by both immunohistochemistry and Western blot.While group Cx43-inhibition,s change is not significant.Conclusion:Hyperbaric oxygen preconditioning can increase the survival ratio of skin flap after the process of ischemia/reperfusion.One of the possible mechanisms is by adapting the inhibition of inflammatory reaction.Cx43 and NF-κB are two of the essentia]substance in this mechanism.Our final research conclusion is through the accommodate of the expression of Cx43 and various inflammatory reaction under the application of hyperbaric oxygen preconditioning,we could inhibit the,chcmotaxis of white bold cells.Finally,we could reach the result of inhibition of inflammatory reaction of ischemia/reperfusion.