The Beneficial Effect of Aminoguanidine on Learning and Memory Impairment in lipopolysaccharide Treated Rats

In the present study, the effect of aminoguanidine (AG) as inducible NO synthase (iNOS) inhibitor on lipopolysaccharide (LPS)-induced learningand memory impairment was evaluated. Materials and Methods: The rats were divided into 5 groups and treated as follow: 1) Control (Saline), 2) LPS (1 mg/ kg), 3-5) AG 50, 100 and 150mg/kg 30 min before LPS injection. The treatment was started 5 weeks beforethe behavioral experiments and continued during the behavioral tests (LPS injection two h before each behavioral experiment). Results: The escape latency in Morris water maze (MWM) test and the latency to enter the dark compartment in Passive avoidance (PA) test in LPS group were significantly higher than in control (P<0.001) whereas, in AG100-LPS and AG150-LPS groups they were shorter than LPS group(P<0.001). Conclusion: It is suggested that LPS induced learning and memory impairments are preventable by aminoguanidine as an iNOS inhibitor.