Glufosinate ammonium stimulates nitric oxide production through N-methyl D-aspartate receptors in rat cerebellum

Glufosinate ammonium, a structural analogue of glutamate, is an active herb icidal ingredient. The neuronal activities of this compound were investigat ed by use of a microdialysis system that allowed us to measure nitric oxide production in the rat cerebellum in vivo, Kainate (0.3-30 nmol/10 mu l), N -methyl-D-aspartate (NMDA) (3-300 nmol/10 mu l) and glufosinate ammonium (3 0-3000 nmol/10 mu l), which were administered through the microdialysis pro be at a rate of 1 mu l/min for 10 min, stimulated nitric oxide production. The glufosinate ammonium-elicited increase in nitric oxide production was s uppressed by an inhibitor of nitric oxide synthase and was antagonized by N MDA receptor antagonists, but not by a kainate/(+/-)-alpha amino-3-hydroxy- 5-methylisoxazole-4-propionic acid receptor antagonist. These results sugge st that glufosinate ammonium stimulates nitric oxide production through NMD A receptors. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.