L-pyroglutamic acid protects rat cortical neurons against sodium glutamate-induced injury

Zhongguo Yao Li Xue Bao. 1999 Aug;20(8):733-6.


Aim: To evaluate the effects of L-pyroglutamic acid (L-PGA, L-5-oxo-2-pyrrolidinecaroxylic acid) on sodium glutamate-induced neurotoxicity in rat cortical neurons.

Methods: In primary cortical cultures from 16-d-old fetal rat, neuronal viability and contents of nitrite in the bathing medium after transient exposure to sodium glutamate (Glu) were measured; with Fura 2-AM as an intracellular calcium indicator, AR-CM-MIC cation measurement system was used to examine cytosolic free calcium ([Ca2+]i).

Results: L-PGA 10-80 mumol.L-1, inhibited Glu (500 mumol.L-1)-induced neuronal loss in a concentration-dependent manner with IC50 value of (41 +/- 9) mumol.L-1 (95% confidence limits: 30.3-54.7 mumol.L-1). L-PGA also attenuated Glu-induced NO release. L-PGA 1, 3, 10, 30, and 100 mumol.L-1 depressed Glu-caused [Ca2+]i elevation by 20.5%, 34.4%, 47.7%, 70.6%, and 80.4%, respectively.

Conclusion: L-PGA protects cortical neurons against Glu-induced neurotoxity which may be related to inhibition of NO formation or suppression of the rise in [Ca2+]i.

MeSH terms

  • Animals
  • Calcium / metabolism
  • Cells, Cultured
  • Cerebral Cortex / cytology
  • Cerebral Cortex / metabolism*
  • Fetus
  • Neurons / metabolism
  • Neuroprotective Agents / pharmacology*
  • Nitric Oxide / metabolism
  • Pyrrolidonecarboxylic Acid / pharmacology*
  • Rats
  • Rats, Sprague-Dawley
  • Sodium Glutamate / antagonists & inhibitors*


  • Neuroprotective Agents
  • Nitric Oxide
  • Calcium
  • Pyrrolidonecarboxylic Acid
  • Sodium Glutamate