SUBCUTANEOUSLY APPLIED MAGNESIUM PROTECTS RELIABLY AGAINST QUINOLINATE-INDUCED N-METHYL-D-ASPARTATE (NMDA)-MEDIATED NEURODEGENERATION AND CONVULSIONS IN RATS - ARE THERE THERAPEUTIC IMPLICATIONS

Quinolinate (QUIN), an agonist of the N-methyl-d-aspartate (NMDA) subtype of the glutamate receptor, was used to model glutamate-induced primary or secondary brain damage. Rats intracerebroventricularly injected with QUIN (1 μmol in 2 μl) showed convulsive reactions and heavy neurodegeneration in the hippocampal formation. MgSO4 (1 M solution injected subcutaneously; 0.6 or 0.3 g/kg) was found to protect completely against QUIN neurotoxicity if administered simultaneously or 1 h after exposure to QUIN. Preliminarily, LD50 for MgSO4 was estimated approximately at 1.2 g/kg. The application of magnesium is discussed to be a potentially powerful therapeutic principle in case of brain injury and convulsive disorders. © 1990.