Effect of L-nitro arginine on neuronal nitric oxide synthase positive neurons distribution,nitric oxide synthase activity and nitric oxide content in hippocampus of Alzheimer's disease model mice

To study the content of NO and the activity of NOS in hippocampus of mice with Alzheimer disease induced by combined administration of D-galactose and aluminium,this paper compared and cured the AD mice models by using NOS inhibitor L-NNA and donepezil hydrochloride.Healthy KM mice 160,the relative body quality between(20±2)g as lab animals,were divided into the model group and control group of normal saline,the treatment group of Alzheimer disease mice with donepezil hydrochloride and L-NNA in random.The mode of Alzheimer disease mice were established by combining administration of D-galactose and aluminium,the content of NO and the activity of NOS of hippocampus were detected every week acrossing the whole process by biochemical technology.The results indicated that the content of NO increased slowly at the beginning,the highest at the fourth week,and then kept high content from 4to 12 weeks.In the two therapy group,the content of NO were extremely notable difference with model group(P0.01 or P0.05),and the group of L-NNA was lower than the group of donepezil hydrochloride between 4to 8weeks(P0.05).The change of NOS and the content of NO in hippocampus are consistent.Using SABC immunohistochemical method to detected the neuronal NOS positive neurons.The density of hippocampus neuronal NOS positive neurons decreased,cell color became light,soma-sectional area and the longest tab became smaller,and were improved significantly after treatment(P0.05).The results suggested that,the high concentrations of No play a neurtoxic role in damage to brain neurons in AD.Donepezil hydrochloride and L-NNA reduced the content of NO in hippocampus,by inhibiting NOS activity,leading a significant protective effect on neurons of hippocampus of Alzheimer disease rats.