Effects of the immunomodulator linomide on macrophage migration and myelinphagocytic activity in peripheral nerve trauma: An experimental study

Wallerian degeneration after peripheral nerve transection leads to the phag ocytosis of degenerated myelin and axon components by macrophages. These ph agocytes are recruited from the systemic circulation and Wallerian degenera tion may therefore be used as a model for myelin removal by hematogenous ma crophages, a feature that is also a hallmark of demyelinating diseases of t he central and peripheral nervous system. The immunomodulator linomide has been shown to be effective in the treatment of experimental demyelinating d iseases although the exact mode of its action is not yet defined, The prese nt study investigated the effect of linomide on monocyte invasion and myeli n phagocytosis after sciatic nerve transection, Linomide had a dual effect in Wallerian degeneration. Monocyte migration from the circulation to the d amaged nervous system was significantly reduced. Additionally, the myelin p hagocytic capacity of macrophages was impaired, finally resulting in a sign ificant delay in the removal of myelin, The present experiments may provide an explanation for the effects of linomide during the course of demyelinat ing diseases of the nervous system.