Myelin basic proteins (MBPs), are major proteins which account for about 30% of total myelin protein content in peripheral nervous system. In several reports some MBPs have been related to mechanisms of nerve regeneration and nerve ligation was shown to alter differentially the expression of MBP from that of P0 in young and adult rats (Setton-Avruj et al. SFN 1999). In this work we have analyzed variations in the expression of MBPs in the sciatic nerve after crush and injection of apotransferrin (Tf). Animals were anaesthetized and their right sciatic nerves exposed at the level of the tigh and injected with 6 μl of Tf. Immediately after the injection, the nerve was crushed proximally to the injection site during 3 sec. Animals were allowed to survive for 1, 3, 7 and 14 days. Sham animals with crushed nerves and saline injections were also prepared. The animals were perfused and the ipsilateral and contralateral sciatic nerves were processed with antibodies against MBPs. The ipsilateral nerve was divided i...