NMDA Neurotoxicity in Murine Cortical Cell Cultures is not Attenuated byHemoglobin or Inhibition of Nitric Oxide Synthesis

摘要

The role of nitric oxide in N-methyl-D-aspartate (NMDA) neurotoxicity wasinvestigated in murine cortical cell cultures. Exposure of cultures. Exposure of cultures to 300um NMDA for 5 min resulted in death of 50-80 percent of neurons over the subsequent 24 h. This injury was not attenuated by hemoglobin, the nitric oxide synthase (NOS) inhibitors NG monomethyl-t-arginine (MMA) or Nw-nitro-K-arginine (NA), or L-arginine depletion. Hemoglobin and NOS inhibitors consistently prevented the increase in cyclic guanosine monophosphate (cGMP) seen after NMDA exposure. These results suggest that NMDA neurotoxicity in this cell system is mediated, at least in part, by mechanisms other than NOS activation.