IMMUNOGENICITY AND REGENERATIVE POTENTIAL OF ACELLULAR NERVE ALLOGRAFTS TO REPAIR PERIPHERAL-NERVE IN RATS AND RABBITS

This study describes the ability of acellular nerve allografts (geneti cally different) to repair injured peripheral nerve in rats and rabbit s. We recently reported the regeneration supporting potential and immu nogenicity of acellular nerve allografts in rats7. The present study e xtends our previous work and quantitates the extent of axonal regenera tion through various nerve grafts in rats. In addition, the use of lon ger nerve grafts to repair rabbit peripheral nerve is described. Inbre d strains of Fischer and Buffalo rats and New Zealand white and Dutch rabbits were used. Acellular grafts were prepared by repeated freezing and thawing of in situ degenerated nerves. Non-frozen predegenerated nerves were used as cellular grafts for comparison. Nerve isografts (g enetically identical) were also performed. The graft length was 2.0 cm in rats and 4.0 cm in rabbits. In both rats and rabbits the cellular isografts showed the most rapid regeneration and target muscle innerva tion. The cellular allografts were invariably rejected and only showed limited regeneration. In contrast, acellular allografts, in spite of their mild immunogenicity, allowed significant regeneration through th em. It is concluded that acellular nerve allografts are capable of sup porting axonal regeneration because of their reduced immunogenicity, a nd thus can be used to bridge nerve gaps after nerve injury.