摘要
目的研究耳鸣大鼠听皮层NMDA(N-甲基-D-天冬氨酸,N-methyl-D-aspartate)受体亚型1、2A、2B(NR1、NR2A、NR2B)的表达变化,从而推测其在耳鸣的发生中可能的作用机制。方法按照随机化原则将动物分成3组,每组9只:A组为耳鸣模型组、B组为生理盐水组、C组为空白对照组。A组通过腹腔注射水杨酸钠并用食物抑制法进行验证。造模成功后运用核酸荧光染料SYBR Green实时荧光定量PCR(Polymerase Chain Reaction,聚合酶链反应)方法检测NMDA受体三种亚型的表达情况。结果NR1在A组的表达显著低于C组(P<0.05),NR2A在A组的表达则显著高于C组(P<0.05),而A、C两组之间NR2B的表达差异比较无统计学意义(P>0.05)。NMDA受体三种亚型B、C两组之间表达差异比较均无统计学意义(P>0.05)。A组NR2A、NR2B与NR1表达量的比值较C组均增大。结论耳鸣大鼠听皮层NMDA受体调节亚基的调控作用增大,突触局部受体蛋白质合成改变,听皮层发生了与NMDA受体相关的可塑性变化,这可能是耳鸣产生的机制之一。
Objective To study expression of N-methyl-D-aspartate （NMDA） receptor subtypes 1 （NR1）,2A （NR2A） and 2B （NR2B） in the auditory cortex in a rat model of tinnitus for their potential roles in tinnitus pathogenesis. Methods Twenty seven rats were randomly divided into three groups （n=9） to receive salicylate as tinnitus models （Group A）,to be treated with normal saline （Group B） or to serve as non-treatment controls （Group C）. Tinnitus modeling was verified through feeding inhibition following intra -peritoneal administration of salicylate. Expression of the three NMDA receptor subtypes was examined by real-time SYBR Green PCR assays. Results NR1 expression in Group A was lower than Group C （p0.05）,while NR2A expression was higher than Group C （p 0.05）. NR2B expression showed no statistically significant difference between Groups A and C. No statistically significant differences were noticed between Groups B and C for either subtype. The rate of expression for all three receptor subtypes was higher in Group A than Group C. Conclusion The data seem to suggest increased regulatory functions by NMDA receptor subtypes in the auditory cortex in rats with tinnitus,which is likely a result of change in protein synthesis in local synapses. This may indicate an NMDA receptor-dependent plastic change in the auditory cortex,which may be a mechanism for tinnitus.
出处
《中华耳科学杂志》
CSCD
2009年第3期216-220,共5页
Chinese Journal of Otology
基金
上海市科委科研计划项目课题(08411961200)
