The effect of ionic redistributions on the microwave dielectric response of cytosol water upon glucose uptake

The sensitivity of cytosol water's microwave dielectric (MD) response to D-glucose uptake in Red Blood Cells (RBCs) allows the detailed study of cellular mechanisms as a function of controlled exposures to glucose and other related analytes like electrolytes. However, the underlying mechanism behind the sensitivity to glucose exposure remains a topic of debate. In this research, we utilize MDS within the frequency range of 0.5–40 GHz to explore how ionic redistributions within the cell impact the microwave dielectric characteristics associated with D-glucose uptake in RBC suspensions. Specifically, we compare glucose uptake in RBCs exposed to the physiological concentration of Ca²⁺ vs. Ca-free conditions. We also investigate the potential involvement of Na⁺/K⁺ redistribution in glucose-mediated dielectric response by studying RBCs treated with a specific Na⁺/K⁺ pump inhibitor, ouabain. We present some insights into the MD response of cytosol water when exposed to Ca²⁺ in the absence of D-glucose. The findings from this study confirm that ion-induced alterations in bound/bulk water balance do not affect the MD response of cytosol water during glucose uptake.