急性热应激与热惊厥幼龄大鼠海马ZnT3 mRNA表达和代谢变化的1H-MRS波谱研究

目的 探讨氢质子磁共振波谱分析(1H-MRS)结合神经病理手段对急性热应激(HS)和热惊厥(FC)后脑神经元代谢和损伤的早期检测价值.方法 采用热水浴诱导21 d龄大鼠FC模型,应用1H-MRS检测HS和FC后脑内N-乙酰天门冬氨酸(NAA)、复合胆碱(Cho)、肌酸(Cr)和乳酸(Lac)含量的变化,原位杂交检测海马锌离子转运体3(ZnT3)mRNA表达.结果 MRS检测结果显示对照组、HS组与FC组NAA/Cr比值分别为1.50±0.42,1.57±0.50和1.61±0.37,Cho/Cr比值分别为0.93±0.27,1.13±0.17和1.28±0.31,各组间差异均无统计学意义(P0.05);Lac/Cr仅见于FC组,为0.64±0.23.FC组海马齿状回检测到ZnT3 mRNA表达.结论 Lac波峰是惊厥性神经元损伤的特征性1H-MRS变化;ZnT3与海马苔藓纤维再生性发芽密切相关;单次短暂的FC发作也能使脑神经元早期发生不同于HS的显著的神经活性物质表达和物质代谢的变化,对脑神经元造成一定的损伤.

Hippocampal Zinc transporter 3 mRNA expression and metabolic changes defined by 1H-MRS in weaning rats following heat stress and febrile convulsion

Objective To asses the value of proton magnetic resonance spectroscopy (1H-MRS) combined with neuropathological findings in early detection of metabolic abnormities and damages of the brain neurons following heat stress (HS) and febrile convulsion (FC). Methods Febrile convulsion models were established in weaning rats (21 days old) by means of hot water bath. -1H-MRS was performed to measure the changes in N-acetylaspartate (NAA), choline (cho), lactate (Lac) and creatine (Cr) contents in the brain tissue following HS or FC, and in sire hybridization was used to detect Zinc transporter 3 (ZnT3) mRNA expression in the hippocampus. Results In the control group, HS group and FC group, the NAA/Cr ratio (1.5±0.42, 1.57±0.59, and 1.61±0.37, respectively) and Cho/Cr ratios showed no significant differences, but a significant increase in Lac/Cr ratio was observed in FC group. ZnT3 3 mRNA expression was detected in the dentate gyms of the rats following the onset of FC. Conclusions As Lac increase is a putative marker of seizure-induced neuronal damage, and ZnT3 is associated with mossy fiber sprouting in the hippocampus, our results suggest that even a single temporary FC may result in marked changes in neuronal metabolism and cause subtle brain injury.