Depolarization of osteoclast plasma membrane potential by 17beta-estradiol.
The effect of estrogen on plasma membrane potential of isolated avian osteoclasts was examined through the use of a fluorescent potential-sensitive dye, bis-(1,3-dibutylbarbiturate) trimethine oxonol, also known as bis-oxonol. A decrease in potential was observed within seconds of addition of 17beta-estradiol. Ouabain, a specific Na+K+-ATPase inhibitor, and BaCl2, an inhibitor of the inwardly rectifying K+ channel, blocked the estrogen response. Verapamil and lanthanum chloride (LaCl3), inhibitors of inward Ca2+ channels, and 4'4-diisothiocyanatostilbene-2'2-disulfonic acid (DIDS), an inhibitor of Cl- channels, did not affect the depolarization. Herbimycin A, a tyrosine kinase inhibitor, also had no effect on the decreased membrane potential. These data provide evidence which suggests that estrogen regulates osteoclasts through ion channel activities. The change in K+ channel activity was observed within seconds of addition of 17beta-estradiol, indicating an action at the level of the plasma membrane.
Brubaker
K D
KD
Department of Biochemistry, The Pennsylvania State University, University Park, Pennsylvania, USA.
Gay
C V
CV
D000818:Animals; D002462:Cell Membrane / Q000502:physiology; D016764:Cell Polarity; D002478:Cells, Cultured; D002645:Chickens; D004958:Estradiol / Q000502:physiology*; D006801:Humans; D008564:Membrane Potentials / Q000502:physiology; D010010:Osteoclasts / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D015221:Potassium Channels / Q000378:metabolism
D015221:Potassium Channels; D004958:Estradiol