Effects Of Longer Conserve Time In Ultra Deep Cryopreservation On Allograft Nerve Transplant

Objective：To study the longer conserve time in ultra deepcryopreservation（-196℃）how to affect the effect of allograft nervetransplant and look for relative longer availability conserve time，takeimmunological rejection of transplant for allograft nerve to theminimum and make the effect of regeneration to the best. At sametime, build models of nerve tissues step by step, so that give benefitsto basis research and clinical therapy. Methods：Divide120femaleWistar rats into three groups by random principle: one group which30rats are sacrificed to get both sides of total60sciatic nerves thenstore in ultra deep cryopreservation; control groups which each grouphave15rats include group A for fresh autologous nerve transplant, group B for fresh allograft nerve transplant; experiment groups whicheach group have15rats obtain group C for the transplant after sciaticnerves store in the ultra deep cryopreservation for3weeks；group Dfor the transplant after sciatic nerves store in the ultra deepcryopreservation for6weeks；group E for the transplant after sciaticnerves store in the ultra deep cryopreservation for9weeks；group Ffor the transplant after sciatic nerves store in the ultra deepcryopreservation for12weeks. Make95%of chloral hydrate usechloral hydrate and distilled water by quality marks5ratio95，make50%of glycerol use glycerol and distilled water by volume marks1ratio1. Anesthesia Wistar rats with95%of chloral hydrate byabdominal injection for0.7ml／100g，then put them on table ofanimal experiment and skin preparation，exposure sciatic nerve cut1.5cm of length through posterior-lateral surface，take a sciatic nervelength about1cm and in total60. Divide the60sciatic nerves into4groups and each group has15，take them in EP tube with50%ofglycerol，then storage them in the bottle of liquid nitrogen in ultradeep cryopreservation accord to different requirements. Nervetransplant，group A the sciatic nerve which transplant on itself；groupB the sciatic nerve which transplant each other；group C transplantafter sciatic nerves store in the ultra deep cryopreservation for3weeks which rewarming with physiological saline in room temperature；group D transplant after sciatic nerves store in the ultradeep cryopreservation for6weeks which rewarming withphysiological saline in room temperature；group E transplant aftersciatic nerves store in the ultra deep cryopreservation for9weekswhich rewarming with physiological saline in room temperature；group F transplant after sciatic nerves store in the ultra deepcryopreservation for12weeks which rewarming with physiologicalsaline in room temperature. The groups Ｃ、D、E、F transplant byrandom principle and with perimysium suture method link4-6needles. Moreover,each group not deal with drugs postoperative.After transplant, observe the relative results of exterior appearance，light microscope，electron microscope and make electrophysilogicaltest. Results：For the exterior appearance result: the condition ofswelling and erosion for groups A、C、D is light, speed of nerve repairis quick,function recovery good postoperative,which group A is thebest, groups C、D are same and close to group A, groups E、F arenext, group B is the worst.Transplant after9weeks, for result ofelectrophysilogical test, the nerve conduction velocity and actionpotential peak for groups A、C、D are same，the P points for groupsA with C、A with D、C with D are all exceed0.05，without obviousdifference;for result of light microscope and electron microscope,groups C and D repair good and without obvious difference, the whole effect near to group A，the lastest is group B. Conclusion：The result of transplant for allograft nerve conserve in the-196℃after3and6weeks are similar, and approach the fresh nerveautograft.