Alpha2-adrenoreceptor agonist, dexmedetomidine, alters acute gene expression after global ischemia in gerbils

The effect of dexmedetomidine, a selective alpha2-adrenoreceptor agonist and neuroprotective agent on the expression of immediate early genes and heat shock protein hsp70, was studied using quantitative in situ hybridization in a global ischemia model. At the dose previously shown to be neuroprotective dexmedetomidine inhibited the expression of c-fos and hsp70 mRNA, did not affect jun-B mRNA, and enhanced the induction of NGFI-A mRNA in the postischemic gerbil hippocampus. The reduced gene expression of c-fos and hsp70 was detected in the CA1 pyramidal cells which are prone to ischemic degeneration, whereas the increased gene expression of NGFI-A was measured from the CA3 and dentate gyrus, areas relatively resistant to ischemia. These alterations in early gene expression possibly reflect the mechanisms mediating the neuroprotective effects of alpha2-adrenoreceptor agonists.