Therapeutical effects of ligustrazine hydrochloride injection on lead poisoning mice and the influence on NO and nNOS of hippocampus

【Objectives】 To study the effects of learning and memory on lead poisoning mice treated by ligustrazine hydrochloride injection and to explore the mechanism preliminarily.【Methods】 The 50 mice were randomly divided into five groups: blank group,negative control group,positive control group,ligustrazine low dose group and high dose group.Step-down test and Morris water maze were performed to evaluate the learning and memory ability of mice.The lead concentrations of blood and brain were measured by electric potential stripping method.In the mean time,the content of NO was tested by nitrate reductase method.The expression of nNOS positive cells was observed by immunohistochemistry methods.【Results】 Compared with that of negative control group,the learning and memory ability of lead poisoning mice was markedly improved in ligustrazine high dose group,and the lead concentrations of blood and brain were significantly decreased,the hippocampal intracellular NO content was obviously increased,and the nNOS positive cells in the CA1 and CA3 region of hippocampus were significantly increased.【Conclusions】 Ligustrazine hydrochloride injection can improve the learning and memory on lead poisoning mice.The mechanism may be related with in-creasing NO content and the expression of nNOS positive cells in hippocampus.