Erythrocyte aging links hypocalcemia to impaired flow dynamics and oxygen transport through volume dysregulation

Older red blood cells (RBCs) show pronounced extracellular calcium dependence to maintain volume stability under fluid shear, with calcium depletion causing post-shear swelling and only partial ATP-dependent recovery.

• Why it matters: Aging RBCs face oxidative and metabolic changes that raise questions about how volume homeostasis persists under mechanical load, and whether volume dysregulation links to microcirculatory dysfunction.
• What they did: Younger and older RBCs were exposed to fluid shear stress under calcium-depleted versus calcium-preserved conditions, assessing volume responses and ATP-dependent recovery, with metabolic deficiency tested in younger cells.
• The result: Calcium depletion selectively impaired older RBC flow behavior and oxygen delivery via shear-induced swelling, while metabolically deficient younger RBCs recapitulated the older swelling phenotype, linking calcium-dependent volume regulation to hypocalcemia-associated vascular dysfunction.