二次脑损伤后大鼠脑皮层代谢型谷氨酸受体亚型4 mRNA的变化

目的：研究弥漫性脑损伤（DBI）及其合并二次脑损伤（SBI）后大鼠脑皮层代谢型谷氨酸受体亚型4（mGluR4)的变化及意义。方法：SD大鼠随机分为正常对照组、假手术组、单纯SBI组、单纯DBI组及合并SBI组,在Marmarou弥漫性脑损伤模型的基础上,制成SBI模型,于伤后1,6,12,24和72h进行HE染色和代谢型谷氨酸受体4亚型（mGluR4)mRNA原位杂交。结果：与正常对照组相比,假手术组和单纯SBI组阳性神经元数以及信号灰度均无明显改变（P＞0．05）;与假手术组相比,单纯DBI组和合并SBI组,mGluR4mRNA表达于脑损伤后1h即有明显增加（P＜0．01）,单纯DBI组在6h达到高峰,合并SBI组于12h达到高峰,此刻与单纯DBI组相比,合并SBI组亦明显增加（P＜0．01）。结论：mGluR4参与了DBI和SBI的病理生理过程。可能为临床救治重型颅脑损伤提供新的理论依据。

Changes of metabotropic glutamate receptor subtype 4 mRNA after diffuse brain injuries coupled with secondary brain insults in rats

AIM To study the changes and effects of metabotropic glutamate receptor subtype 4 (mGluR4) after diffuse brain injuries (DBI) coupled with secondary brain insults (SBI) in rats. METHODS 105 male SD rats were randomized into five groups: normal control group, sham operated group, SBI alone group, DBI alone group, DBI coupled with SBI group. The SBI model was made on a basis of Marmarou model. The brain sections were stained with H&E and the mRNA of mGluR4 were detected in 1, 6, 12, 24, 72 h after injuries by hybridization in situ . RESULTS Statistical analysis showed no significance between normal control group, sham operated group and SBI alone group ( P > 0.05 ). The animals exposed to DBI with/without SBI showed a significant expression of mRNA of mGluR4 compared to the sham operated animals 1 h after injuries ( P < 0.01 ). The expression reached the highest level in DBI alone group at 6 h. But it would still increase in DBI with SBI group 6 h after injuries, and reached the peak at 12 h. At this moment, the results showed a significant increase in DBI with SBI group rather than in DBI alone group ( P <0.01). CONCLUSION mGluR4 might play a role in the pathophysiology of DBI and SBI, which would provide a new method for severe brain injury therapy.