Urea concentrating ability of artificial renal tubule based on countercurrent multiplier system using electrodialysis, dialysis and filtration

Abstract

Countercurrent multiplier systems have been found in various organs of various animal species. In a mammalian kidney, countercurrent multiplier system plays an important role in the process of urine concentration. An artificial renal tubule which can concentrate urea is one of the key elements to develop a wearable artificial kidney for the patients currently undergoing intermittent hemodialysis therapy. The objective of the present study was to develop a biomimetic artificial renal tubule based on the countercurrent multiplier system. We mimicked active transport of NaCl at ascending limbs of the Henle loop by electrodialysis and mimicked passive transport of the solute and water transport via water channel at descending limbs and collecting ducts by dialysis and filtration. The membranes used for electrodialysis, dialysis and filtration were placed parallel to each other to establish countercurrent configuration. We examined urea concentrating ability of the fabricated prototype module of artificial renal tubule based on the countercurrent multiplier system. The fabricated prototype module was capable of concentrating urea approximately 1.3 fold. These results indicate that the countercurrent multiplier system is useful to develop an artificial renal tubule. © 2009 Springer-Verlag.