| Objective: To evaluate the effect of the peripheral nerve regeneration inthe adult wistar rats,which had been made a 1.0cm long gap in the continuity ofthe sciatic nerve and the gap was repaired by SD rats nerves after removal ofschwann cell and myelin sheath by chemical extraction to get acellular basallamina tubes , on which triiodothyronine(T3) was applied. Methods: Ten adult female Sprague-Dawley Hannover and wistarHannover rats , weighing around 250 grams and 200 grams respectively wereused . Sprague-Dawley rats were killed by an i.p. injection with sodiumpentobarbital (0.5ml, 60mg/ml). The sciatic nerves were excised ,cleaned fromexternal debris and treated with chemical detergents to become Acellularallografts containing schwann cell basal lamina tubes , which were observed theeffect of removed schwann well and myelin sheath with histological,morphological exammations. A neutral PH sterile solution of triiodo-L-thyronine(sigma) (0.5mg of T3 was dissolved in 0.5ml 0.01N NaOH , and then thesolution is neutralized with 0.01N Hcl ,the final PH is 7.8) was impregnated in0.5ml gelatin hydrogels(0.3g of gelatin was dissolved in 2ml distilled water) .Eight-hundred microliters triiodothyronine solution containing both T3 gelatinhydrogels was poured onto the surface of the graft after the graft had beensutured to the host nerve in the syringe immediately. According to differentways of peripheral nerve grafting , the wistar rats were divided randomly intothree groups , 10 in each : acellular basal lamina tubes grafting combined withT3(group A) , allogeneic nerve grafting(group B) and autogenous nervegrafting(group C).The sciatic nerve function index(SFI) , electrophysiologicaltest, the weight of triceps surae, light and electron microscopic and imagineanalysis were done postoperatively . Results: After sciatic nerve transplantation ,regeneration of peripheralnerve occurred in three groups. All the data were analysed by analysis ofvariance. The output demonstrated that SFI was higher in group C than bothgroup A and group B at postoperatively 8 weeks (P<0.01) , and there was nosignificant difference between group A and group C(P>0.05). However , SFIwas higher in both group A and group C than group B (P<0.01) , and there wasno significant difference between group A and group C(P>0.05) . Motor nerveconductive velocity(NCV) , the recovery ratio of relative potential ,the weightof triceps surae and the cross area of myelinated nerve fibers were significantlybetter in both group A and group C than group B(p<0.01) , and there was nosignificant difference between group A and group C (P>0.05) at postoperative 8weeks and 12 weeks respectively . Analysis of serveal transmission electronmicrographs taken from group A ,group B and group C at 12 weeks afteroperation showed that the percentage of myelinated axons and the thickness ofthe myelin sheaths remained greater in both group A and group C than group B ,there was no significant difference between group A and group C , and therewere proliferation of schwann cells more actively and maturer myelin sheaths ingroup A and than group B. Conclusions: The acellular basal lamina tubes grafting combined withT3 can improve nerve regeneration by enhancing the growth of regeneratingaxons and migration of schwann cell , and is better than the acellular basallamina tubes grafting , which is a good subsitute for nerve grafts.
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