Enalapril increases synaptophysin expression in the hippocampus of streptozotocin-induced diabetic rats

Objective To explore the effects of enalapril on spatial learning and memory,and to identify synaptophysin expression in hippocampus of streptozotocin-diabetic rats.Methods Forty rats were randomly divided into control group,diabetic model group and the enalapril treatment group.Streptozotocin-diabetic rat model was developed.The diabetic rats were treated with enalapril for 12 weeks.Then,the learning and memory abilities of rats were tested with Morris water maze;mRNA and protein expression of synaptophysin in hippocampus was detected by RT-PCR and immunostaining.Results Compared with diabetic model group,the enalapril treatment group showed a significant decrease in the mean time of escape latencies(P0.05),an increase in percentage of stay time in the central area and the frequency of passing the original platformposition(P0.05).In addition,both synaptophysin protein expression and mRNA expression increased significantly(P0.05)in hippocampus of streptozotocin-diabetic rats following enalapril treatment.Conclusion Enalapril may improve the learning and memory capability through increasing the expression of synaptophysin in the hippocampus of streptozotocin-diabetic rats.