Gow, I.F. and Thomson, Jean and Davidson, Jillian and Shennan, D.B. (2005) The effect of a hyposmotic shock and purinergic agonists on K+(Rb+) efflux from cultured human breast cancer cells. BBA - Biomembranes, 1712 (1). pp. 52-61. ISSN 0005-2736Full text not available in this repository. (Request a copy from the Strathclyde author)
The effect of a hyposmotic shock and extracellular ATP on the efflux of K+(Rb+) from human breast cancer cell lines (MDA-MB-231 and MCF-7) has been examined. A hyposmotic shock increased the fractional efflux of K+(Rb+) from MDA-MB-231 cells via a pathway which was unaffected by Cl− replacement. Apamin, charybdotoxin or removing extracellular Ca2+ had no effect on volume-activated K+(Rb+) efflux MDA-MB-231 cells. An osmotic shock also stimulated K+(Rb+) efflux from MCF-7 cells but to a much lesser extent than found with MDA-MB-231 cells. ATP-stimulated K+(Rb+) efflux from MDA-MB-231 cells in a dose-dependent fashion but had little effect on K+(Rb+) release from MCF-7 cells. ATP-stimulated K+(Rb+) efflux was only inhibited slightly by replacing Cl− with NO3−. Removal of external Ca2+ during treatment with ATP reduced the fractional efflux of K+(Rb+) in a manner suggesting a role for cellular Ca2+ stores. Charybdotoxin, but neither apamin nor iberiotoxin, inhibited ATP-stimulated K+(Rb+) release from MDA-MB-231 cells. Suramin inhibited the ATP-activated efflux of K+(Rb+). UTP also stimulated K+(Rb+) efflux from MDA-MB-231 cells whereas ADP, AMP and adenosine were without effect. A combination of an osmotic shock and ATP increased the fractional efflux of K+(Rb+) to a level greater than the sum of the individual treatments. It appears that the hyposmotically-activated and ATP-stimulated K+ efflux pathways are separate entities. However, there may be a degree of 'crosstalk' between the two pathways.
|Keywords:||hyposmotic shock, purinergic agonist, breast cancer cell, Pharmacy and materia medica, Biochemistry, Cell Biology, Biophysics|
|Subjects:||Medicine > Pharmacy and materia medica|
|Department:||Faculty of Science > Strathclyde Institute of Pharmacy and Biomedical Sciences|
|Depositing user:||Strathprints Administrator|
|Date Deposited:||12 May 2010 10:45|
|Last modified:||22 Jul 2016 02:15|