Cell viability and laminin-induced neurite outgrowth in cultures of embryonic chick neural tube cells: effects of cytosine-B-D-arabinofuranoside.

We have measured the effects of cytosine-beta-D-arabinofuranoside (AraC) on cell survival and neurite outgrowth in cultures of dissociated 4-6 day embryonic chick neural tube cells. High concentrations of AraC (greater than 100 microM) reduced neuronal cell survival and neurite outgrowth from viable cells. Concentrations normally used to inhibit mitotic cell division (1-10 microM) were toxic to the neurones cultured in serum free medium on a poly-DL-ornithine/laminin substrate. AraC does not appear to have a neurite promoting effect on dissociated neurones that are cultured in the presence of low numbers of non-neuronal cells. This suggests that the neurite promoting effects of AraC reported by others is likely to be through the non-neuronal cells that were an inherent feature of the culturing systems in these studies. AraC cytotoxicity was completely blocked by the addition of the competitive antagonist: 2'deoxycytidine (2'DC) but not by its metabolic precursor cytosine (cyt). We suggest that the acute effects of AraC on neurones which are actively growing neurites are the result of interference with lipid metabolism.