The presence of vermipodia-like processes on the free surfaces of multicellular spheroids composed of adult rat hepatocytes in the primary culture

The presence and function of vermipodia-like processes of hepatocytes-multicellular spheroids formed in primary culture was described. Cine microscopy and scanning electron microscopy revealed that about 1-5% hepatocytes in single cell after culture initiation already posessed the processes. The processes disappeared when the hepatocytes attached and spread, and than appeared again on the surface of multicellular spheroides. The processes were moving by extending, shrinking and twisting, and sometimes extended 50 um. Five to ten percent of spheroids had 1-5 processes. Occasional collision of two spheroids resulted in the fusion of spheroids after their processes intertwined, attached to the partner spheroid and shrunk. Electron microscopy revealed that the processes were larger in size than the numerous microvilli co-present on the free surface of spheroids and their cytoplasm had scarece orgalella. The morphological characterisitcs of the processes most resembled those of vermipodia reported in histiocytic leukemia cells.