CYCLOHEXIMIDE AND ACTINOMYCIN-D BLOCK THE TOXIC EFFECT OF GLUTAMIC-ACID ON PC12 CELLS

PROGRAMMED cell death is considered to play a key role during developm ent and also during physiopathological events such as neurodegenerativ e diseases and ischaemia. We have recently shown in PC12 cells that gl utamate induces a progressive cytotoxicity which is only visible 8-10 h after incubation with glutamate for at least 4-6 h. We now present e vidence that the toxic action of glutamate may correspond to programme d cell death because it is blocked by either actinomycin D or cyclohex imide. This effect, however, may not be due to apoptosis since it is n ot blocked by aurintricarboxylic acid, a non-specific inhibitor of end onucleases, and neither chromatin condensation nor DNA fragmentation o r liberation is seen after glutamate treatment.