The influence of culture media on embryonic renal collecting duct cell differentiation.

During kidney development the embryonic ampullar collecting duct (CD) epithelium changes its function. The capability for nephron induction is lost and the epithelium develops into a heterogeneously composed epithelium consisting of principal and intercalated cells. Part of this development can be mimicked under in vitro conditions, when embryonic collecting duct epithelia are isolated from neonatal rabbit kidneys and kept under perfusion culture. The differentiation pattern is quite different when the embryonic collecting duct epithelia are cultured in standard Iscove's modified Dulbecco's medium as compared to medium supplemented with additional NaCl. Thus, the differentiation behavior of embryonic CD epithelia is unexpectedly sensitive. To obtain more information about how much influence the medium has on cell differentiation, we tested medium 199, basal medium Eagle, Williams' medium E, McCoys 5A medium, and Dulbecco's modified Eagle medium under serum-free conditions. The experiments show that in general, all of the tested media are suitable for culturing embryonic collecting duct epithelia. According to morphological criteria, there is no difference in morphological epithelial cell preservation. The immunohistochemical data reveal two groups of expressed antigens. Constitutively expressed antigens such as cytokeratin 19, P CD 9, Na/K ATPase, and laminin are present in all cells of the epithelia independent of the culture media used. In contrast, a group of antigens detected by mab 703, mab 503, and PNA is found only in individual series. Thus, each culture medium produces epithelia with a very specific cell differentiation pattern.