Characterization of short- and long-term cultured goat peripheral blood monocytes

Goat peripheral blood mononuclear cells were isolated, using Ficoll-sodium diatrozoate. Monocytes were separated by adherence and maintained in culture for up to 50 days. By 24 hours of culture and after removal of nonadherent cells, there were 94.2 +/- 5% of the adherent cells classifiable as monocytes based on nonspecific esterase staining. Greater than 98% of these cells were phagocytic. Approximately 94% had receptors for the Fc portion of bovine immunoglobulin G, and 86% had receptors for equine complement. Cytochemically, goat monocytes were positive for nonspecific esterase, acid phosphatase, glucuronidase, lactate dehydrogenase, succinic dehydrogenase, and glycogen, regardless of culture duration when tested. Results for specific esterase, peroxidase, and Sudan black staining varied from faint to negative. The esterase staining pattern of cultured monocytes was characterized by light and electron microscopies. Ultrastructurally, esterase activity was limited to the cell membrane. Intracytoplasmic esterase activity was not recognizable in normal monocytes or in monocytes containing phagocytized particles.