Properties of stretch-activated K+ channels in an G292 osteoblast-like cell / 대한치과교정학회지
Korean Journal of Orthodontics
; : 197-204, 2000.
Article
in Korean
| WPRIM (Western Pacific)
| ID: wpr-647600
Responsible library:
WPRO
ABSTRACT
K+ -selective ion channels were studied in excised inside-out membrane patches from human osteoblast-like cells(G292). There classes of K+ channels were present and could be distinguished on the basis of conductance. Conductances were 270+/-27 pS, 113+/-12 pS, 48+/-8 pS according to their approximate conductances in symmetrical 140 mM KCI saline at holding potential of -80 mV. It was found that the small conductance (48 pS) K+ channel activation was dependent on membrane voltage. In current-voltage relationship, small conductance K+ channel showed outward rectification, and it was activated by the positive potential inside the membrane. In recordings, single channel currents were activayed by a negative pressure outside the membrane. The membrane pressure increased P(open) of the K+ channel in a pressure-dependent manner. In the excised-patch clamp recordings, G292 osteoblast-like cells have been shown to contain three types of K+ channels. Only the small conductance (48 pS) K+ channel is sensitive to the membrane stretch. These findings suggest that a hyperpolarzing current, mediated in part by this channel, may be associated with early events during the mechanical loading of the osteoblast. In G292 osteoblast-like cells, K+ channel is sensitive to membrane tension, and may represent a unique adaptation of the bone cell membrane to mechanical stress.
Full text:
Available
Database:
WPRIM (Western Pacific)
Main subject:
Osteoblasts
/
Stress, Mechanical
/
Cell Membrane
/
Ion Channels
/
Membranes
Limits:
Humans
Language:
Korean
Journal:
Korean Journal of Orthodontics
Year:
2000
Document type:
Article