二次脑损伤后大鼠脑皮层代谢型谷氨酸受体亚型4mRNA的变化

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

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(m Glu R4)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 ,2 4和 72 h进行 HE染色和代谢型谷氨酸受体 4亚型(m Glu R4) m RNA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 .0 5 ) ;与假手术组相比 ,单纯 DBI组和合并 SBI组 ,m Glu R4m RNA表达于脑损伤后 1h即有明显增加 (P<0 .0 1) ,单纯 DBI组在 6 h达到高峰 ,合并 SBI组于 12 h达到高峰 ,此刻与单纯 DBI组相比 ,合并 SBI组亦明显增加 (P<0 .0 1) .结论 m Glu R4参与了 DBI和 SBI的病理生理过程 。

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.