Characteristics of cultured human renal cortical epithelia

Nine human kidney epithelial cell lines, isolated from small biopsied material and from whole kidney, were propagated in both a hormonally defined medium and a medium supplemented with serum. At confluency, hemicysts or domes, typical of cultured epithelial cells, were formed by these cells. Monolayers had junctional complexes between cells and the presence of numerous microvilli on the cell surface. Parathyroid hormone markedly stimulated these cells to produce cyclic AMP. They also contained high levels of gamma-glutamyltranspeptidase, leucine aminopeptidase, and maltase, enzymes that are associated with the brush-border membrane of the proximal tubule. The cultured cells demonstrated the ability to transport amino acids and alpha-methylglucoside, a substrate actively transported only by the proximal tubule in the kidney. Based on these findings, the cultured cells reflected a number of characteristics associated with the proximal tubule. These renal epithelial cell lines may provide a useful model for studying various aspects of human renal physiology and biochemistry.