Parallel changes in intracellular water volume and pH induced by NH(3)/NH(4)(+) exposure in single neuroblastoma cells.

Background: Increased blood levels of ammonia (NH3) and ammonium (NH4(+)), i.e. hyperammonemia, leads to cellular brain edema in humans with acute liver failure.

Simultaneous measurement of water volume and pH in single cells using BCECF and fluorescence imaging microscopy.

Regulation and maintenance of cell water volume and intracellular pH (pHi) are vital functions that are interdependent; cell volume regulation affects, and is in turn affected by, changes in pHi. Disruption of either function underlies various pathologies. To study the interaction and kinetics of these two mechanisms, we developed and validated a quantitative fluorescence imaging microscopy method to measure simultaneous changes in pHi and volume in single cells loaded with the fluorescent probe BCECF.