| Objective: To study the effect of nerve regeneration through bridging the gap of rat sciatic nerve with acellular basal laminea tubes removed Schwann cell and myelin sheath.Methods: 30 healthy Sprague-Dawley rats and 20 Wistar rats of both sexes,weighing 200~22og, were used in the study, the 25mm nerve segment for grafting were obtaining from left sciatic nerves of Wistar rats, ten sciatic nerves were selected randomly. Acellular basal lamina tubes were acquired from normal rat sciatic nerves which were treated with nondenaturing biological detergents made up of lysophosphatidylcholine, sodium azide and so on. The animals were anaesthetized with 20% urethane (2mg/kg), the sciatic nerves of left hind limb were exposed and a 20mm segment of the nerve were trasected. They were divided randomly into three groups, 10 SD rats in each group, respectivly. acellular basal lamina tubes graft (group A); autogenous nerve bridging (group B); allogenic nerve bridging (group C). The grafts of acellular basal lamina tubes were sutured to the epineurium of the proximal and distal stumps with fore sutures (9-0 Ethilon) under an operating microscope at each junction in the group A; autografting was performed by swapping a 20mm long nerve segment in the left sciatic nerve of the same rat, and the autografts were sutured to the nerve stumps as described above in the group B; and allogenic grafts were bridged the the gap in the group C. Electrophysiological was used to examina the latency and amplitude of motor evoked potential of regenerating nerve fiber at 8w , 12w. Histomorphometry, Electromyographic and Image analysis were determined at 2 and3 months post operation.Results: 1.general view: the left hindlimb of rats in group C had developed a change of swelling, ulcer formation and lose of toes, not healing at 12w post operation, while only 2 and 3 in group A and B showed the same symtons at 3w and completely healing of the ulcer at 12w.stimulating the left hindlimb with nod and water of 70 C, animals showed reflex and constraction in group A and B, but no any reflex in group C. There were servely local adhesion in the lesion of sciatic nerve, no nerve fibers had been found to bridge the gap in group C; 2.Electromyography the latency and amplitude of regenerating nerve were examined at 2 months, they were 3.37 + 0.54ms, 13.82 + 1.73mv respectively in group A, and 2.82 0.49ms, 17.45 + 151mv respectively in groupB, the latency and wave amplitude of regenerating nerve in group A were lower than that in group B (ta=2.101, p<0.05; tb=5.00, p<0.05). At three months, the latency and wave amplitude of regenerating nerve were 2.74 0.49msx 19.02 2.32mv respectivly in group A, and 2.32 0.46ms, 21.04 1.09mv respectively in group B, there was no statistical difference in both groups, no regenerating nerves were found to bridge the gaps and cicatrices formed, the results could not be acquired. 3.methylene blue-basic magenta staining and electron microscopy Regenerating nerve were arranged in bundles in group A and B, there were minifascicle formation and a large amount of proliferated collagen in between the minifascicled, no cicatrices form, regenerating vasa spread randomly, electron microscopy show a large number of myelinated and unmyelinated fiber arranged in buddies. The regenerative sprouting of fibers were surrounded by Schwann cell, thick myelinated axons were found, there were no statistical difference in group A and B. 4.Image analysis the number , diameter and the thickness of myelin sheath of regenerating nerve fibers were 2904 410.82, 3.63 0.43 m and 0.83 + 0.13um respectively in group A in third months; and 3113.00 390.04, 3.97 0.32 m, 1.32 0.24um respectively in group B. the thickness of myelinated axon in group A was inferior to group B (ta=5.68, p<0.05) at 3 months, while the number and diameter of axons in both groups were similar.Conclusion: The grafts is found to support outgrowth of axons and migration of Schwann cell, and is a good tool to use in peripheral nerve regeneration.
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