| Abstract: | Monkey bone marrow-derived adherent cells were maintained in culture for six months. Phase contrast and scanning electron microscopy showed two cell shapes: fusiform and polygonal. No difference was observed in the cyto-chemical staining of the two shapes. Both stained positively for alpha-napthyl acetate esterase, acid phosphatase, collagens I and III, and lipids and negatively for peroxidase and factor VIII antigen. A small proportion (1.5%) were alkaline phosphatase-positive. An average of 14% of the cells were phagocytic in the primary culture, but this proportion decreased progressively with passage. Fc receptors were not detected, while C3 receptors were detected in 1% of primary cultured cells in primary culture, but were not detected in subcultured cells. Adherent cells were not evident in cultures supplemented with 10 mM ammonium acetate. These findings indicate that monkey marrow-derived adherent cells are fibroblastoid in nature. |
