In vitro culture of the proximal tubule of the bovine nephron : the fate of the histiospecific antigens and neosynthesis of an alpha-foetoprotein.
The isolation of pure tubules of the outer cortex of the foetal bovine kidney, using a previously described methods, has shown that the tubule suspension obtained is almost entirely constituted of proximal tubule fragments. The proximal cells obtained from this suspension were grown in vitro. The previously called "nephrospecific" antigens NS1-2 were shown to be strictly specific for the cells of the proximal tubule, which is an "histion" of the kidney, that is to say an ultimate unit of differentiation of this organ. The fate of these antigens, henceforth termed "histiospecific antigens" (of the proximal tubule), was followed in primary monolayer cultures of the proximal tubules, using immunodiffusion tests and immunofluorescence. A rapid decrease in this antigen content of the cells was observed during the in vitro culture. An immunoautoradiographic study demonstrated that the synthesis of these antigens was switched off in the confluent cultures. A similar autoradiographic study demonstrated that these same proximal cells at confluence synthesized a bovine alpha1-foetoprotein, which had been detected in earlier studies of kidney cortex cultures. This double antigenic shift is correlated with the in vitro evolution of some morphological markers of the proximal cells, as studied with the transmission and the scanning electron microscope. The factors responsible for these results are discussed.
D000818:Animals; D000937:Antigen-Antibody Reactions; D000941:Antigens / Q000032:analysis; D001345:Autoradiography; D002417:Cattle / Q000276:immunology*; D000939:Epitopes; D005326:Fetal Proteins / Q000096:biosynthesis*; D005455:Fluorescent Antibody Technique; D005779:Immunodiffusion; D066298:In Vitro Techniques; D007668:Kidney / Q000276:immunology*; D007672:Kidney Cortex / Q000276:immunology; D007687:Kidney Tubules, Proximal / Q000254:growth & development / Q000276:immunology*; D009399:Nephrons / Q000276:immunology*; D000509:alpha-Fetoproteins / Q000096:biosynthesis*
D000941:Antigens; D000939:Epitopes; D005326:Fetal Proteins; D000509:alpha-Fetoproteins