Yajie Zhang1, Marie Poirier-Quinot1, Charles S. Springer, Jr.2, James A. Balschi1
1Physiological NMR Core Laboratory, Brigham & Women's Hospital, Boston, MA, United States; 2Advanced Imaging Research Center, Oregon Health & Science University, Portland, OR, United States
The mean intracellular water lifetime, τi, is a DCE-MRI parametric biomarker proportional to (size)/PW, where (size) and PW are mean linear cell size and cell membrane water permeability coefficient measures, respectively. Cell suspension studies allow precise τi measurement and manipulation of its determinant factors. Here, yeast cells are treated with ebselen, an inhibitor of the cell membrane H+ATPase. Oxygenation of anaerobic yeast decreases τi. This decrease is inhibited by ebselen. This demonstrates that PW has an active component reflecting nano-osmotic coupling. Rapid, equilibrium trans-membrane water cycling is driven in part by homeostatic ion cycling.