title: Potentiometric platform for the quantification of cellular potassium efflux.
abstract: Renewed interest in the measurement of cellular K(+) effluxes has been prompted by the observation that potassium plays an active and important role in numerous key cellular events, in particular cell necrosis and apoptosis. Although necrosis and apoptosis follow different pathways, both induce intracellular potassium effluxes. Here, we report the use of potassium-selective microelectrodes located in a microfluidic platform for cell culture to monitor and quantify such effluxes in real time. Using this platform, we observed and measured the early signs of cell lysis induced by a modification of the extracellular osmolarity. Furthermore, we were able to quantify the number of dying cells by evaluating the extracellular potassium concentration. A comparison between the potentiometric measurement with a fluorescent live-dead assay performed under similar conditions revealed the delay between potassium effluxes and cell necrosis. These results suggest that such platforms may be exploited for applications, such as cytotoxicological screening assays or tumor cell proliferation assays, by using extracellular K(+) as cell death marker.
authors.affiliation: Department of Engineering Physics and Biomedical Engineering Institute, Ecole Polytechnique de Montréal, C.P. 6079, succ. Centre-ville, Montréal, (Québec) H3C 3A7, Canada.
authors.forename: Silvia
authors.initials: S
authors.lastname: Generelli
authors.forename: Renaud
authors.initials: R
authors.lastname: Jacquemart
authors.forename: Nico F
authors.initials: NF
authors.lastname: de Rooij
authors.forename: Mario
authors.initials: M
authors.lastname: Jolicoeur
authors.forename: Milena
authors.initials: M
authors.lastname: Koudelka-Hep
authors.forename: Olivier T
authors.initials: OT
authors.lastname: Guenat
mesh_terms: D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D048429:Cell Size; D002470:Cell Survival; D002477:Cells / Q000378:metabolism*; D006801:Humans; D007668:Kidney / Q000166:cytology; D008839:Microelectrodes; D046210:Microfluidic Analytical Techniques / Q000379:methods*; D008856:Microscopy, Fluorescence; D009994:Osmolar Concentration; D011188:Potassium / Q000378:metabolism*; D011199:Potentiometry / Q000379:methods*; D012680:Sensitivity and Specificity; D013997:Time Factors
chemical_list: D011188:Potassium