Intracellular lumina and bile canaliculi in rat hepatocytes in vitro--a cytochemical study.

Within a few hours after being placed in culture, isolated rat hepatocytes reassociate into clusters and differentiate intercellular cavities bordered by junctional complexes. These structures bear a strong resemblance to the bile canaliculi found in the liver. If the plating is impaired by permanent agitation, intracellular lumina surrounded by microvilli appear in the cytoplasm of some isolated hepatocytes. The formation of these structures which mostly contain an osmiophilic substance is enhanced by cAMP and they probably result from modifications in the functioning of the Golgi complexes as suggested by thiamine pyrophosphatase cytochemistry. It may be speculated that these intracellular lumina may be functionally related to new bile canaliculi differentiated between reassociated cells.