Alterations in the expression of lipid and mechano-gated two-pore domain potassium channel genes in rat brain following chronic cerebral ischemia.

To determine the gene expression level of the lipid-sensitive mechano-gated 2P domain K(+) channels in rat cortex and hippocampus after chronic cerebral ischemia, TREK-1, TREK-2 and TRAAK were detected in rats at 3 and 30 days after permanent bilateral carotid artery ligation (BCAL). By using reverse transcription-polymerase chain reaction, we found that TREK-1 and TREK-2 mRNA had no obvious changes in cortex after ischemia, while TRAAK mRNA was significantly increased by 70% after 30 days. In hippocampus, the gene expressions of TREK-1 and TRAAK were increased markedly at 3 days (97% and 87%, respectively) and 30 days (63% and 47%, respectively) after ischemia. However, TREK-2 gene expression level had no change. In-situ hybridization results also showed that TREK-1 gene expressing-positive neurons were increased significantly in cortex and hippocampus after permanent BCAL for 3 and 30 days. These molecular studies provide evidence for an involvement of the lipid-sensitive mechano-gated 2P domain K(+) channels in the BCAL model, which might have neuroprotective effects in cerebral ischemia.