Evaluation of Na+ Active Transport and Morphological Changes for Bioartificial Renal Tubule Cell Device Using Madin-Darby Canine Kidney Cells

The function of current hemodialysis as an artificial kidney is insufficient because of the lack of reabsorptive function. In this study, we intend to develop a bioartificial renal tubule cell device (RTD) using tubular epithelial cells and artificial membranes and to evaluate the reabsorptive function of the confluent layers. Madin-Darby canine kidney (MDCK) cells were cultured on a nucleopore polycarbonate membrane for up to 4 weeks after confluence to examine the influence of the culture period on their ability to transport Na+ actively using Na+/K+ATPase (NKA). The results were (1) active Na+ transport of the cells averaged 24.8 mM/m2 ⋅ 24 h during the initial 2 weeks after confluence and then decreased to about 4.2 mM/m2 ⋅ 24 h during the next 2 weeks; (2) NKA localized on the basal-lateral sides of the cells during the initial 2 weeks, whereas it also localized on the apical side of the cells during the next 2 weeks; (3) long-term culture resulted in an increased number of upheaving cell mass, incre...