Modulation of hTREK-I by carbon monoxide

TREK-I is a background K+ channel important in the regulation of neuronal excitability. Here, we demonstrate that recombinant humanTREK-I is activated by low concentrations of carbon monoxide (CO) and nitric oxide (NO), applied via their respective donor molecules. Related channels hTASK-I and hTASK-3 were unaffected by CO. Effects of both CO and NO were prevented by preincubation of cells with the protein kinase G inhibitor, Rp-8-Br-PET-cGMPS. The effects of CO were independent of NO formation. At higher concentrations, both NO and CO were inhibitory. As both NO and CO are important neuronal gasotransmitters and TREK is crucial in regulating neuronal excitability, our results provide a novel means by which these gases may modulate neuronal activity.