[G-protein modulates the inhibition of angiotensin II on BKCa in ECV304].
OBJECTIVE
To investigate the effect of angiotensin II (A II) on maxi-conductance calcium-activated potassium channel(BKCa) activity in ECV304 cell membrane, and the possible involvement of G-protein.


METHODS
Cell-attached configuration of patch clamp technique was employed to record the current of BKCa in ECV304.


RESULTS
10(-7) mol/L angiotensin II inhibited the BKCa activity. Current amplitude and open probability were decreased, open time was shortened and close time was increased. G-protein activation could eliminate the inhibition of A II.


CONCLUSIONS
A II significantly decreased the activity of BKCa in ECV304, which might depolarize the membrane, and the stability of membrane might change. Thus endothelial cell dysfunction might be induced. G-protein activation was involved in the regulation of the above A II inhibition process.
Lin
L
L
Department of Physiology, Institute of Basic Medical Sciences, CAMS, PUMC, Beijing 100005, China.
Zheng
Y
Y
Qu
J
J
Bao
G
G
D000804:Angiotensin II / Q000494:pharmacology*; D002478:Cells, Cultured; D019204:GTP-Binding Proteins / Q000502:physiology; D006801:Humans; D018408:Patch-Clamp Techniques; D026902:Potassium Channel Blockers / Q000494:pharmacology*; D024681:Potassium Channels, Calcium-Activated / Q000187:drug effects* / Q000502:physiology; D014471:Umbilical Veins / Q000166:cytology
D026902:Potassium Channel Blockers; D024681:Potassium Channels, Calcium-Activated; D000804:Angiotensin II; D019204:GTP-Binding Proteins