Dose-Response Relationship of Phloretin Therapy on Water and Glucose Transport during Experimental Peritoneal Dialysis.

Background: Water retention, ultrafiltration insufficiency, and metabolic complications due to abnormally high glucose concentrations are still common problems in patients treated with peritoneal dialysis. Phloretin, a nonselective inhibitor of facilitative glucose transporter channels (GLUT), has shown to improve water transport and lower glucose absorption in experimental peritoneal dialysis. However, the dose-response relationship remains unknown, and we therefore performed a dose-response study to elucidate the pharmacodynamic properties of intra-peritoneal phloretin therapy.

Methods: Experimental peritoneal dialysis was performed in fifty healthy Sprague-Dawley rats, using glucose-based dialysis fluid containing five different concentrations of phloretin. We utilized radiolabeled 18F-deoxyglucose (18-FDG) to determine the plasma-to-dialysate transport. The data was then analyzed to determine the dose-response relationship of phloretin according to the Hill-model equation.

Results: Intraperitoneal phloretin therapy followed a dose-response relationship where higher concentrations of phloretin lowered the diffusion capacity of 18-FDG and conventional glucose, while enhancing ultrafiltration. Phloretin showed high potency for water removal and diffusion outcomes, requiring low concentrations to achieve substantial effects.

Conclusions: Intraperitoneal phloretin therapy followed a distinct dose-response relationship, showing high potency in improving ultrafiltration and reducing glucose absorption in experimental PD. These findings support the therapeutic potential of GLUT-inhibitors like phloretin and support future clinical studies to evaluate efficacy and optimal dosing in patients undergoing PD.