Development and characterization of a rat histiocyte-macrophage tumor line.

A transplantable macrophage-like cell line has been obtained and established in W rats. This cell line is in its 85th passage and is perhaps the only established macrophage-like cell line that grows rapidly intraperitoneally in rats. The cells possess some of the typical characteristics of macrophages, such as adherence to glass, phagocytosis, presence of Fc receptors and C3d receptors, la determinants, leukocyte common antigen, lysozyme, non-specific esterase, and glycogen. The tumor also grows as solid when injected sc, intradermally, or intramuscularly. The cells have collagenase, tyrosine-specific protein kinase, and several other hydrolases. Histopathologic and ultrastructural observations suggest it to be a histiocytic tumor. The availability of a macrophage cell line of rat origin provides a useful experimental model to study different macrophage functions at the cellular and molecular level.