Moderate Exercise Training Enhances Aquaporin-1 Mediated Erythrocyte Osmotic Deformability and Aerobic Capacity in Patients with End-Stage Renal Disease

This study aimed to evaluate the effects of exercise training on AQP1-mediated erythrocyte osmotic deformability in ESRD patients.

Twenty-five ESRD patients underwent moderate-intensity exercise training for 30 min·d⁻¹, 3 d·wk⁻¹ for 6 months. Data from ten age-matched healthy subjects were used for baseline comparison. All blood samples were analyzed using osmotic gradient ektacytometry, and HgCl₂ was applied to inhibit AQP1 to assess its role in mediating osmotic deformability.

At baseline, ESRD patients exhibited significantly reduced erythrocyte osmotic deformability, with diminished HgCl₂-treated EImax, Omax, EIhyper, Ohyper, and area under the curve (AREA), indicating impaired AQP1-mediated responses compared to healthy controls. Following moderate-intensity exercise training, significant improvements were observed in both erythrocyte osmotic deformability and VO_2max in ESRD patients. Training led to a marked increase in AQP1 content, which enhanced HgCl₂-treated EImax, Omax, and Ohyper, as well as improved the AQP1-suppressed AREA. Regression analysis showed that the increase in AQP1-mediated osmotic functions under hypertonicity was closely linked to the upregulation of AQP1 expression.

Moderate-intensity exercise training significantly improves both erythrocyte osmotic deformability and aerobic capacity in ESRD patients. AQP1 expression, initially reduced in ESRD patients, increased after training, correlating with enhanced AQP1-mediated osmotic function, particularly under hypertonic conditions.

These findings underscore the critical role of AQP1 in erythrocyte physiology and suggest that exercise training could be an effective therapeutic strategy to enhance fitness and erythrocyte functionality in ESRD patients.