抄録
Phosphate (P) retention is well recognized in chronic renal failure (CRF). Although P restriction and use of P binder such as aluminum are widely recommended to prevent its accumulation, the former causes mal-nutrition due to the deficiency of protein intake, furthermore in the latter, aluminum may be one of the etiological substances for dialysis encephalopathy or osteomalacia in hemodialysed patients. Hemodialysis or hemofiltration can remove P, but in compact artificial kidney system without using dialysate or substitution fluid, it is necessary to develope new methods for P removal. As zirconium (Zr) is able to adsorb P and has been utilized in dialysate recovery system, we examined adsorptive capacity of ZrO2, and ZrO(OH)2for P and applied them for direct hemoperfus ion (DHP).
Gram of powdered Zr adsorbed about 5.5mg of P, which was similar as powdered aluminum did. Zr beads encapsulated with gelatin and glutaraldehyde represented 30-60% reduced P adsorptive capacity. However, the smaller beads showed the better adsorptive capacity and Zr beads in size of 9 mesh adsorbed about 4.5mg of P/g of Zr.
On DHP with 60g of Zr microcapsule, serum P decreased significantly in P loaded acute renal failure dogs. Serum calcium was also reduced mildly but insignificantly.
These results indicate that DHP with Zr microcapsule is useful to treat hyperphosphatemia in CRF patients, and further investigations such as application of Zr for the oral adsorbent may be required.
