Investigation on Water Dynamics in Cell Swelling

Motivation: Water is essential for the functioning of cells. Goal(s): This study investigates water dynamics involved in cell swelling, a common physiological cellular phenomenon, using MRI. Approach: We measured magnetization transfer (MT) to evaluate changes in the free water pool under two cell swelling conditions: hypoosmotic stress and [K+] elevation. Results: Results show that cell swelling leads to an increase in the free water pool within a voxel, diluting the intracellular space. Additionally, T2 increased more in response to hypotonic stress than to [K+] elevation in the same cell volume, probably due to the different degree of dilution in the intracellular space. Impact: This study elucidates the water dyanmics associated with cell swelling using MRI, particualrly showing differences between two different mechanisms of cell swelling, which will contribute significantly to a better understanding of cell physiology and function.