Transferrin effects on myelin basic protein and PGP expression in the sciatic nerve after resection of dorsal root ganglia L4-L6

P.L. MUSOLINO; M.F. CORONEL; J.M. PASQUINI; E.F. SOTO; C.P. SETTON-AVRUJ; M.J. VILLAR

Orlando, USA

Congreso; Society for Neuroscience; 2003

Society for Neuroscience

Myelin basic protein (MBP) accounts for about 30% of total myelin protein content of peripheral nerves. MBP redistribution with the appearance of immunoreactive clusters was seen in the distal stump of ligated sciatic nerves (Setton-Avruj et al., 2002) abd following colchicine injection into the nerve (Aquino et al., SFN 2002). The peak of appearance of protein clusters is observed at 7 days post-injury. In this work we have analyzed the expression of MBPs and PGPs in the sciatic nerve after the extraction of the right 4th, 5th and 6th lumbar dorsal root ganglia and its variation following transferrin (Tf) injection into the nerve. Animals were anaesthetized and their right dorsal root ganglia L4-6 were extracted. A group of animals was then injected with 2 ml of TF into the nerve at the level of the thigh. Contralateral structures were used as controls. Animals were allowed to survive for after 1, 3, 7, 14, 21 and 28 days. Sham animals were also prepared. The animals were perfused and their sciatic nerves were processed with antibodies against MBPs and PGPs. The results showed a normal pattern of MBP-like immunoreactivity (LI) in contralateral sciatic nerve and in sham operated animals. Cluster formation was observed along the entire extension of the injured nerves with a pattern of distribution similar to that observed after sciatic nerve ligation or colchicine administration. Tf injection in ganglionectomized animals showed a significantly lower appearance of clusters of MBPs-LI. Thus, Tf induced a protective function for maintenance of the myelin sheet in injured nerves. The mechanisms by which this reorganization takes place is currently under study.