Protective Effects of Aminoguanidine against Sodium Metavanadate-Induced Spatial Memory Retention Impairment in Morris Water Maze

Vanadium is a potential neurotoxic agent widely distributed in the environment. Understanding the neurotoxic mechanisms of vanadium on learning and memory seems necessary. We investigated the time-dependent (1-week, 2- week and 4-week) effects of sodium metavanadate (SMV) (25 mg/kg/day; pre-training oral administration) and 4-day intraperitoneal injections of aminoguanidine (AG) as a selective inducible nitric oxide synthase inhibitor (10, 50, and 100 mg/kg) on spatial memory retention in Morris water maze. Animals were trained for 4 days and tested 48 h after the last training trial. The data showed that 4-week oral pre-treatment with SMV (25 mg/kg/day) induced spatial memory retention deficits and decreased the time spent in the target quadrant. We found that 4-day administration of different doses of AG during training trials significantly decreased the time and distance of finding the hidden platforms. Additionally, SMV-induced spatial memory retention impairments were prevented in animals received combined SMV (25 mg/kg/day, 4 weeks) and AG (10 mg/kg/day, 4 days). Our findings showed the protective role of AG on SMV-induced spatial memory retention deficits.