HIGHLY POLARIZED PRIMARY UROTHELIAL CELLS FROM HUMAN URETER GROWN AS SPHEROID-LIKE VESICLES

Epithelial cells growing in vitro are frequently non-polarized and lac k histophysiological characteristics. Furthermore, the quality of two- dimensional cell layers is limited by the physico-chemical properties of the support. Therefore, for an in vitro system to reflect the norma l epithelial physiology, it is necessary to maintain the inner and out er geometrical configuration of the cells. In order to avoid the disad vantages of two-dimensional cultures we have established an in vitro m odel that closely resembles the in vivo situation. Human ureteral epit helial cells (HUEC) were used to prepare multicellular vesicles which maintain a geometrically intact cell organization that is not achieved in conventional cultures. Light and electron microscopy investigation s showed the morphology of the cells to be similar to that in situ. HU EC vesicles are more in vivo-like than two-dimensional cultures and th erefore represent a suitable model for a variety of research purposes including studies on the pathogenesis of micro-organisms.