Cell membrane stretch activates intermediate-conductance Ca2+-activated K+ channels in arterial smooth muscle cells
- نوع فایل : کتاب
- زبان : انگلیسی
- مؤلف : Yasunobu Hayabuchi Yutaka Nakaya Kazuaki Mawatari Miki Inoue Miho Sakata Shoji Kagami
- چاپ و سال / کشور: 2010
Description
The aim of this study is to determine the signal transduction of membrane stretch on intermediate-conductance Ca2?-activated K? (IKca) channels in rat aorta smooth muscle cells using the patch-clamp technique. To stretch the cell membrane, both suction to the rear end of patch pipette and hypotonic shock were used. In cellattached and inside-out patch configurations, the open probability of IKca channels increased when 20- to 45-mmHg suction was applied. Hyposmotic swelling efficiently increased IKca channel current. When the Ca2?- free solution was superfused, the activation of IKca current by the hyposmotic swelling was reduced. Furthermore, gadolinium (Gd3?) attenuated the activation of IKca channels induced by hyposmotic swelling, whereas nicardipine did not. In the experiments with Ca2?-free bath solution, pretreatment with GF109203X, a protein kinase C (PKC) inhibitor, completely abolished the stretch-induced activation of IKca currents. The stretch-induced activation of IKca channels was strongly inhibited by cytochalasin D, indicating a role for the F-actin in modulation of IKca channels by changes in cell stretching. These data suggest that cell membrane stretch activates IKca channels. In addition, the activation is associated with extracellular Ca2? influx through stretch-activated nonselective cation channels, and is also modulated by the F-actin cytoskeleton and the activation of PKC.
Heart Vessels (2011) 26:91–100 DOI 10.1007/s00380-010-0025-0 Received: 4 September 2009 / Accepted: 21 January 2010 / Published online: 10 November 2010
