MACROPHAGE-ENHANCED NEURITE REGENERATION OF ADULT DORSAL-ROOT GANGLIANEURONS IN CULTURE

TO study the effects of macrophages on nerve regeneration, purified lo w population dorsal root ganglia (DRG) neurones from adult mice were c ultured in protein-free medium (PFM) or in conditioned media (CM) from peritoneal macrophages cultured in PFM. In PFM, only 20% of the neuro nes survived at 5 days in culture, but the macrophage CM more than dou bled the proportion of neurone survival and neurite extension of contr ols. These factors did not act on superior cervical ganglia (SCG) neur ones, and were considered as being proteins because of their trypsin-s ensitive property. Additionally, they may be different from the previo usly known neurotrophic factors derived from macrophages, because the target cells and effective concentration of these factors were differe nt from those of known ones. The factors investigated in this study ma y play an important role in nerve regeneration.