The presence of arachidonic acid-activated K+ channel, TREK-1, in human periodontal ligament fibroblasts.
Human periodontal ligament (PDL) fibroblasts expressed following two-pore-domain K(+) channels, TWIK-2 > TREK-1 > TWIK-1 >> TASK-1 > TRAAK > TASK-2. TREK-2 message was not detectable. We found the presence of arachidonic acid-activated and mechanical stress-sensitive K(+) channel, TREK-1, in the PDL fibroblasts by patch-clamp technique. It was also found the significant increase of intracellular concentration of arachidonic acid upon the application of cyclic stretch. Therefore, we suppose that the mechanical stretch due to the mastication activates phospholipase A(2) to release arachidonic acid (AA) from membrane, then, the released AA activates TREK-1. Thus, TREK-1 K(+) channels may play a protective role to maintain the negative membrane potential of PDL fibroblasts against the environmental stimuli.
Saeki
Yukikazu
Y
Department of Basic Science for Health and Nursing, Shiga University of Medical Science, Ohtsu, Shiga, Japan. ysaeki@belle.shiga-med.ac.jp
Ohara
Akito
A
Nishikawa
Masanori
M
Yamamoto
Takahiro
T
Yamamoto
Gaku
G
D016718:Arachidonic Acid / Q000502:physiology*; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid; D004305:Dose-Response Relationship, Drug; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D008563:Membrane Lipids / Q000378:metabolism; D018408:Patch-Clamp Techniques; D010513:Periodontal Ligament / Q000187:drug effects / Q000378:metabolism*; D024683:Potassium Channels, Tandem Pore Domain / Q000187:drug effects / Q000502:physiology*; D012313:RNA / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013314:Stress, Mechanical