title: Metabolic substrates alter attachment and differentiated functions of proximal tubule cell culture.
abstract: Proximal tubules cultured in vitro gradually lose their differentiated functions. Because standard culture media lacks several substrates important for renal proximal tubule oxidative metabolism, whether a mixture of substrates including butyrate, alanine, and lactate (BAL) would modify growth and/or differentiated function of proximal tubular cells in culture was examined. Tubules cultured in media supplemented with 2 mM butyrate, alanine, and lactate exhibited enhanced attachment but did not exhibit an altered growth rate. Higher levels of phosphoenolpyruvate carboxykinase and leucine-amino peptidase were sustained, although these activities were still diminished in comparison with that in fresh tubules. Sodium-dependent glucose uptake and dome formation--other reflections of epithelial cell differentiated function--also were enhanced. These studies demonstrate that the substrates used to culture proximal tubules can modify both their attachment and their manifestation of differentiated function in culture.
authors.affiliation: Department of Medicine, University of Southern California, Los Angeles.
authors.forename: M J
authors.initials: MJ
authors.lastname: Tang
authors.forename: R L
authors.initials: RL
authors.lastname: Tannen
mesh_terms: D000409:Alanine / Q000494:pharmacology; D000818:Animals; D002087:Butyrates / Q000494:pharmacology; D020148:Butyric Acid; D002448:Cell Adhesion / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D003470:Culture Media; D007687:Kidney Tubules, Proximal / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D007773:Lactates / Q000494:pharmacology; D019344:Lactic Acid; D011817:Rabbits
chemical_list: D002087:Butyrates; D003470:Culture Media; D007773:Lactates; D020148:Butyric Acid; D019344:Lactic Acid; D000409:Alanine