Changes of metabotropic glutamate receptor subtype 1 a in diffuse brain injury with secondary brain insults and the effects of 2-methyl-4-carboxyphenylglycine

摘要

Objective: To observe the changes of metabotropic glutamate receptor la in rat brain in a rodent model of diffuse head injury with secondary insults and the effects of 2-methyl-4-carboxyphenylglycine (MCPG). Methods: Based on Marmarous rodent model of diffuse brain injury ( DBI), hypotension was made by blood withdrawal as secondary brain insults (SBI). 105 male SD rats were randomized into A and B groups. The changes of mGluR_(1a) in cerebral cortex were studied by immunohistochemistry and the effect of MCPG by HE. Each group was divided into different subgroups at different time after injury. Results: Compared with that of sham group, the number of mGluR_(1a) positive neuron increased by 12.9 +-3.2 (P<0.05) 1 day after injury in the injured cerebral cortex in DBI group. However, in DBI and SBI group there was a more significant increase in the number of mGluR_(1a) positive neuron at 4 hours after injury (15.6 +-3.0, P < 0.05) and then the number of mGluR_(1a) positive neuron gradually decreased. Administration of MCPG reduced total cortical necrotic neurons counts on the 7th day after injury (5.21 +-2.52, P<0.05). Conclusions: Brain injury can increase the gene expression of mGluR_(1a) and the role of mGluR_(1a) may be a key factor in the aggravation of head injury with SBI, and that MCPG may have therapeutic potential in head injury.