Figure 2.

Functional imaging of primary CPP clearance using 2-photon intravital microscopy. Mice received intravenous injections of primary CPP prepared with fluorescent fetuin-A, and the major clearance organ liver was continuously recorded for up to 1 h. Fluorescent intensity was quantified in regions of interest (ROI) and clearance kinetics were calculated. Representative still micrographs with typical views of primary CPP clearing cells are shown. (A) Primary CPP clearance from sinusoids into liver sinusoidal endothelial cells (LSEC) occurred within 1 min, and into Kupffer cells within 2 min. Thereafter, primary CPP in Kupffer cells were rapidly degraded, shown by a fast decline of the signal after about 15 min. (B) Overview showing a sector of a liver lobule. (C) Calculation of mean fluorescence intensity in the sinusoids, LSEC, and Kupffer cells determined by ROI quantification.