RESUMEN
Malakoplakia in kidney of rats was caused experimentally by injection of large quantities of not purified endotoxin-antigen complex of Escherichia coli 0 75 (O. coli 127 97 CDC 0 group 75; American Type Culture Collection, Eight Edition 1968, page 24). The extract in the beginning became surrounded by leukocytes, later by macrophages. The latter then were transformed into characteristic Hansemann cells. From the 8th day on started the depletion of calcium phosphate in the cytosegresomes of macrophages, thus forming the Michaelis-Guttmann bodies, necessary for the diagnosis of malakoplakia. It is believed that complex of endoxin- and antigen of Escherichia coli may take a part - at least in certain cases - in formation of malakoplakia in human.