Sex-specific expression of N-methyl D-aspartate receptor (NMDAR) in the preoptic area of neonatal rats

The relationship between the N-methyl-D-aspartate receptor (NM DAR) and the sex-specific neurotoxicity of L-glutamate on the preoptic area (POA) of ne onatal rats was studied. The NMDAR were semiquantified by western blot anal ysis. The kinetic change of intracellular calcium and lactate dehydrogenase (LDH) efflux were monitored as rapid and delayed toxic signals, respective ly. The results showed that: (1) the NMDAR expression in POA of male rat is higher than that of females; (2) the L-glutamate (500 mu M) induced a more significant elevation of intracellular calcium in neuron derived from male rat than that from female; (3) after glutamate-treatment, the LDH efflux i n neuronal culture of male rat is higher than that of females. These result s suggest that the quantitative difference in NMDAR between male and female rats may contribute to the sex-specific neurotoxicity of L-glutamate on th e POA of neonatal rats. (C) 1999 Elsevier Science Ireland Ltd. All rights r eserved.