戊四氮诱导大鼠癫痫模型中前脑磷酸化DARPP-32与嗜酸损伤神经元的相关性研究

Relationship between Phosphorylated DARPP-32 and Neuronal Damage in Forebrain of Rat with Pentylenetetrazol-induced Epilepticus

目的研究在重复系统给予亚惊厥剂量戊四氮(PTZ)诱导的癫痫持续状态模型中,DARPP-32在大鼠前脑的磷酸化表达分布情况及其时程变化与嗜酸损伤神经元时程变化之间的可能联系,以探讨磷酸化DARPP-32(p-DARPP-32)在实验性大鼠癫痫模型中存在的神经元损伤所扮演的角色。方法健康成年雄性SD大鼠35只,采用随机数字表法分为5个实验组(n=5)和1个对照组(n=10),A组:PTZ 1 h,大鼠在PTZ诱发癫痫发作1 h后被处死,后几组按相应的时间处死;B组:PTZ6 h;C组:PTZ24 h;D组:PTZ48 h;E组:PTZ72 h;对照组大鼠接受同样体积和次数的0.9%氯化钠溶液腹腔注射,而后在与上述各组相应的时间点被处死。采用免疫组织化学及苏木素-伊红染色法检测不同组大鼠皮质、海马和纹状体p-DARPP-32阳性神经元数量和嗜酸损伤神经元数量。结果不同组大鼠皮质、海马和纹状体p-DARPP-32阳性神经元数量比较,差异均有统计学意义(P<0.05);其中与对照组比较,A组、B组、C组、D组、E组大鼠皮质、海马和纹状体p-DARPP-32阳性神经元数量均升高(P<0.05);A组与B组比较,差异均无统计学意义(P>0.05);C组较A组和B组均降低(P<0.05);D组和E组较C组均降低(P<0.05);D组与E组比较,差异均无统计学意义(P>0.05)。不同组大鼠皮质、海马和纹状体嗜酸损伤神经元数量比较,差异均有统计学意义(P<0.05);其中与对照组比较,A组、B组、C组、D组、E组大鼠皮质、海马和纹状体嗜酸损伤神经元数量均升高(P<0.05);B组较A组均升高(P<0.05);C组较B组均升高(P<0.05);C组、D组、E组比较,差异均无统计学意义(P>0.05)。结论 SE发作后DARPP-32在大鼠前脑存在着明显磷酸化表达,且与嗜酸损伤神经元数量的时程变化有着一致的同步关系。持续的癫痫发作后,多巴胺激活D1/PKA/DARPP-32/PP-1信息传递链可能是导致大鼠前脑神经元广泛性损伤的重要原因之一,而p-DARPP-32在多巴胺发挥生理作用方面扮演着重要角色。

Objective To explore the distribution of phosphory lated DARPP-32（p-DARPP-32）inratforebrain and the relationship between the change process of p-DARPP-32 and acidophilic neurons after the onset of epilepticus , and to further deduce that p-DARPP-32 is possibly involved in neuronal damage resulted from epilepsy induced by repetitive injections ofsubconvulsivedosesofpentylenetetrazol（PTZ）.Methods 35healthyadultmaleSDratswererandomlydividedinto5exper-iment groups （n=5） and one control group （n=10） .Group A： 1 h PTZ, and the rats were killed 1 h after the onset of epilep-ticus （ SE） .Group B： 6 h PTZ;Group C： 24 h PTZ;Group D： 48 h PTZ;Group E： 72 h PTZ.The control group was given 0.9% sodium chloride solution with the same volume and frequency , and the rats were killed at the same time.Immunohistochemistry and Hematoxylin and Eosin staining were used to assess the p-DARPP-32 positive neurons and aci-dophilic neurons in cortex , hippocampus and corpus striatum .Results The p-DARPP-32 positive neurons in cortex , hippo.