Altered glycine transport by cerebral tissue and decreased Na+ and Ca++ pump activities during organophosphorus-ester–induced delayed neurotoxicity development period

Uptake of U-¹⁴C] glycine during the organophosphorus-ester-induced delayed neurotoxicity (OPIDN) development period was studied. Diisopropyl fluorophosphate (DFP), a delayed neurotoxic organophosphorus ester was administered to adult rats and hens. Results showed a decreased accumulation of glycine in hen cerebral cortex slices during the delayed neurotoxicity development period. An altered sensitivity toward transport inhibitors 2,4-dinitrophenol and ouabain was observed in DFP-treated hens. An altered neuronal membrane function during the OPIDN development period is reported in the present work. Brain Na⁺, K⁺-ATPase and Ca⁺⁺-ATPase activities decreased during the neurotoxicity development period. The decrease in Ca⁺⁺-ATPase activity persisted in hens until the complete development of neurotoxic symptoms. Decreased Ca⁺⁺ pump activity is correlated with altered membrane function during OPIDN. © 1996 John Wiley & Sons, Inc.