Biphasic effects of H(2)O(2) on BK(Ca) channels.
The inhibitory or activating effect of H(2)O(2) on large conductance calcium and voltage-dependent potassium (BK(Ca)) channels has been reported. However, the mechanism by which this occurs is unclear. In this paper, BK(Ca) channels encoded by mouse Slo were expressed in HEK 293 cells and BK(Ca) channel activity was measured by electrophysiology. The results showed that H(2)O(2) inhibited BK(Ca) channel activity in inside-out patches but enhanced BK(Ca) channel activity in cell-attached patches. The inhibition by H(2)O(2) in inside-out patches may be due to oxidative modification of cysteine residues in BK(Ca) channels or other membrane proteins that regulate BK(Ca) channel function. PI3K/AKT signaling modulates the H(2)O(2)-induced BK(Ca) channel activation in cell-attached patches. BK(Ca) channels and PI3K signaling pathway were involved in H(2)O(2)-induced vasodilation and H(2)O(2)-induced vasodilation by PI3K pathway was mainly due to modulation of BK(Ca) channel activity.
Liu
Bo
B
Huazhong University of Science and Technology, Wuhan, PR China.
Sun
Xiaohui
X
Zhu
Yanhong
Y
Gan
Lu
L
Xu
Huibi
H
Yang
Xiangliang
X
D000818:Animals; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D057809:HEK293 Cells; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D051036:Large-Conductance Calcium-Activated Potassium Channels / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D051379:Mice; D018408:Patch-Clamp Techniques; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D015398:Signal Transduction / Q000187:drug effects; D014664:Vasodilation / Q000187:drug effects
D051036:Large-Conductance Calcium-Activated Potassium Channels; D006861:Hydrogen Peroxide; D019869:Phosphatidylinositol 3-Kinases