戊四氮点燃模型大鼠Cdk5活性与苔藓纤维出芽相关性

目的研究戊四氮(PTZ)点燃模型大鼠细胞周期素依赖性激酶5(Cdk5)活性改变与苔藓纤维出芽(MFS)动态变化的相关性。方法将120只雄性成年大鼠随机分为PTZ组和对照组,PTZ组连续每天腹腔注射PTZ30mg/kg,对照组同时注射等体积生理盐水。按戊四氮第1次给药后3d、1、2、4和6周各随机分为5个亚组。每个亚组再随机分为2个小组:一组用于液体闪烁计数仪测定各时间点大鼠海马的Cdk5活性;另一组用于Timm染色检测苔藓纤维出芽情况。结果 PTZ组MFS评分3d时增加,2周达高峰并维持至6周;海马Cdk5活性3d时增加,2周达高峰,4周下降,6周恢复对照组水平;较对照组有显著差异。额区Cdk5活性各时间点之间及与对照组之间均无显著性差异。结论 Cdk5可能通过活性增高参与苔藓纤维出芽,从而促使癫发生。

The relation relativity between dynamic changes of Cdk5 Activity and mossy fiber sprouting in PTZ kindling model rat

Objective To investigate the relationship between cyclin-dependent kinase 5（Cdk5） activity and mossy fiber sprouting（MFS） of hippocampal in the pentylenetetrazole（PTZ） kindling model.Methods Rats were assigned randomly into PTZ treated and control groups.The rats of PTZ treated groups were intraperitoneally injected PTZ（30mg/kg） every 24 hours.The rats of control groups received 0.9% saline injections instead of PTZ at the same time.At 3 d,1 w,2 w,4 w and 6 w after the first PTZ injection,the Cdk5 activity was analyzed with a liquid scintillation counter respectively,while Timm staining was scored in the CA3 region of hippocampus and dentate gyrus.Results The Timm scores of PTZ group,which gradually increased from 3 d to 2 w,maintained high levels in the 4 w and 6 w groups.The levels of Cdk5 activity in hippocampus were significantly higher at the PTZ treated groups in 3 d,1 w,2 w,and 4 w than those of controls.Thereafter,the activity decreased to the levels of controls.The levels of Cdk5 activity in lobus frontalis had no significance at the PTZ treated groups of all the time points as well as those of controls.Conclusions Cdk5 may play a role in epileptogenesis through influencing moss fiber sprouting by its elevated activity.