The cerebrospinal fluid oxidized NO metabolites, nitrite and nitrate, in Alzheimer's disease and vascular dementia of Binswanger type and multiple small infarct type.

The concentration of the nitric oxide (NO) metabolites nitrite (NO2-) and nitrate (NO3-) in the cerebrospinal fluid from patients with Alzheimer's disease (AD), vascular dementia of the Binswanger type (VDBT) or multiple small infarct type (MSID), and controls were determined using high performance liquid chromatography. The nitrite concentration was significantly higher in VDBT/MSID patients than in controls (p < 0.005). The nitrate concentration and the combined nitrite and nitrate concentration was significantly higher in both AD (p < 0.05) and VDBT/MSID (p < 0.001) patients than in controls, with these concentrations being significantly greater in VDBT/MSID than AD patients (p < 0.005). The combined nitrite and nitrate concentration significantly decreased as the severity of dementia progressed in AD (rs=0.70, p < 0.01), but remained elevated in all stages of VDBT/MSID. These results suggest that NO production or oxidation in the brain increases in the early stage of AD and then decreases as neuronal cell loss progresses, but increases throughout the course of disease in VDBT/MSID, which may in part contribute to neuronal degeneration in both conditions.