Increased clearance of indoxyl sulphate in renal failure rats with the addition of water-soluble poly-β-cyclodextrin to the dialysate.

Abstract

Indoxyl sulphate (IS), a protein-bound uremic toxin that dramatically increases in the sera of patients with end-stage renal disease (ESRD), is poorly removed by conventional haemodialysis (HD). The purpose of this study was to explore whether the addition of water-soluble sorbent poly-β-cyclodextrins (PCDs) to dialysate can increase the clearance of IS in uremic rats in vivo. Male SD rats (450-550 g, n = 18) with nephrectomy plus IS injection (10-mg/kg) were randomly divided into three groups: 1. The HD group (n = 6): conventional HD for 4 h; 2. the 2% PCD group: 2% PCD added to the dialysate, HD for 4 h; and 3. the 4% PCD group: 4% PCD added to the dialysate, HD for 4 h. The serum IS levels in model rats were similar to those of ESRD patients. A stable and safe rat HD treatment mode was established by adjusting the vascular access, blood flow rate, dialysate flow rate, dialysis pipe, dialysate configuration, temperature, treatment environment, and other aspects. Our study found that adding 2% PCD to dialysate significantly improved the clearance of IS approximately twofold compared with conventional HD. Further increasing the PCD concentration to 4% did not increase IS clearance. Therefore, our study showed that adding water-soluble sorbent PCDs to dialysate significantly improved the clearance of IS in uremic rats in vivo.