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

During kidney development the embryonic ampullar collecting duct (CD) epith elium changes its function. The capability for nephron induction is lost an d the epithelium develops into a heterogeneously composed epithelium consis ting of principal and intercalated cells. Part of this development can be m imicked 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 collect ing duct epithelia are cultured in standard Iscove's modified Dulbecco's me dium as compared to medium supplemented with additional NaCl. Thus, the dif ferentiation 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 t o morphological criteria, there is no difference in morphological epithelia l cell preservation. The immunohistochemical data reveal two groups of expr essed antigens. Constitutively expressed antigens such as cytokeratin 19, P -CD 9, Na/K ATPase, and laminin are present in all cells of the epithelia i ndependent of the culture media used. In contrast, a group of antigens dete cted by mab 703, mab 503, and PNA is found only in individual series. Thus, each culture medium produces epithelia with a very specific cell different iation pattern.