CELL-CELL INTERACTIONS ARE ESSENTIAL FOR MAINTENANCE OF HEPATOCYTE FUNCTION IN COLLAGEN GEL BUT NOT ON MATRIGEL

The objective of this study was to examine the importance of cellular aggregation for the maintenance of liver-specific functions in hepatoc ytes. We used two culture matrix systems (collagen sandwich and Matrig el) to examine the responsiveness of albumin secretory function in cul tured rat hepatocytes under various seeding conditions. With high cell seeding, both culture systems elicited comparable levels of elevated function. Under conditions of sparse seeding, however, their responses were quite distinct: collagen sandwiched cells exhibited a significan t deterioration in secretion, while Matrigel-cu Itu red cells retained their basal levels of function. This indicates that a critical degree of cell-cell interactions is essential for promoting function in the collagen sandwich, and in the Matrigel-cultured cells functions may be preserved by constitutive matrix-related phenomena, even in the absen ce of aggregation. (C) 1997 John Wiley & Sons, Inc.