Referenced in: none

Automatically associated channels: Kir6.1 , Kir6.2

Title: Dexmedetomidine directly inhibits vascular ATP-sensitive potassium channels.

Authors: Takashi Kawano, Fumimoto Yamazaki, Haidong Chi, Shinji Kawahito, Satoru Eguchi

Journal, date & volume: Life Sci., 2012 Feb 13 , 90, 272-7

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/22155038

Abstract
Dexmedetomidine is reported to have an effect on peripheral vasoconstriction; however, the exact mechanisms underlying this process are unclear. In this study, we hypothesized that dexmedetomidine-induced inhibition of vascular ATP-sensitive K(+) (K(ATP)) channels may be associated with this vasoconstriction. To test this hypothesis, we investigated the effects of dexmedetomidine on vascular K(ATP)-channel activity at the single-channel level.We used cell-attached and inside-out patch-clamp configurations to examine the effects of dexmedetomidine on the activities of native rat vascular K(ATP) channels, recombinant K(ATP) channels with different combinations of various inwardly rectifying potassium channels (Kir6.0 family: Kir6.1, 6.2) and sulfonylurea receptor subunits (SUR1, 2A, 2B), and SUR-deficient channels derived from a truncated isoform of Kir6.2 subunit, namely, Kir6.2ΔC36 channels.Dexmedetomidine was observed to inhibit the native rat vascular K(ATP) channels in both cell-attached and inside-out configurations. This drug also inhibited the activity of all types of recombinant SUR/Kir6.0 K(ATP) channels as well as Kir6.2ΔC36 channels with equivalent potency.These results indicate that dexmedetomidine directly inhibits K(ATP) channels through the Kir6.0 subunit.