NITRIC-OXIDE SYNTHASE-CONTAINING NEURONS IN THE HIPPOCAMPUS ARE PRESERVED IN TRIMETHYLTIN INTOXICATION

We studied the effects of trimethyltin (TMT) (9 mg/kg, p.o.) on the ni tric oxide synthase (NOS)-containing neurons in the rat hippocampus by NADPH-diaphorase histochemistry and a biochemical assay of NOS activi ty. TMT exposure caused the typical behavioral changes and a loss of t he CA3/4 pyramidal cells, which were NADPH diaphorase-negative, The sc attered interneurons and the CA1 pyramidal cells, which were NADPH dia phorase-positive, were spared. Hippocampal NOS activity showed no redu ction in the TMT-treated rats compared with the controls. These result s provide evidence of the preservation of the NOS-containing neurons i n TMT intoxication.