Fig. 5.

Organ-specific differences in vascular permeability to PLD. The accumulation of i.v. injected PLD to the tumors was (A) imaged and (B) quantified. Bar indicates 100 μm. * Indicates p < 0.05 versus brain and mfp. 4T1 tumors growing in brain, mfp, or liver were identified by accumulation of CD204-positive tumor-associated macrophages into the tumors. Macrophages in the liver (Kupffer cells) were also positively stained with a CD204 antibody. (C) The percentage of endothelial cells tightly covered by basement membrane in the tumors growing in the different organs. * Indicates p < 0.05 versus liver. (D) Intravital microscopy of the 4T1 tumors growing in mfp or liver probed with fluorescent dextran tracers of two sizes injected i.v. (Molecular Weight (MW) = 3000 Da (red) and =40,000 Da (green)). (E) Quantification of the fluorescent intensities of the tracers indicated by the white lines in D. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)