Figure 6.

Fluorescence micrographs of cultured liver sinusoidal endothelial cells (LSEC). Cultures were prepared as described in the Methods section. The cultures were fixed in 4% paraformaldehyde, after 6 h of incubation. FITC-labeled formaldehyde-treated serum albumin (FSA) and TRITC-labeled monodisperse polymer particles (MDPP) were administered intravenously prior to isolation of liver cells. Fluorescent microscopy reveals a homogeneous LSEC culture contaminated by a few cells with TRITC-MDPP and lipid containing vacuoles. The green fluorescence from endocytosed FITC-FSA demonstrates that most cells are LSEC, and that the probe is localized in cytoplasmic vacuoles (A), whereas the yellow fluorescence from phagocytosed TRITC-MDPP identifies Kupffer cells (arrows) (B). Autofluorescence from vitamin A identifies stellate cells (arrows) (C). (Scale bars; 20 μm).