The role of endothelial cell caveolae in the uptake and transport of macromolecules from the
blood-space to the tissue-space remains controversial. To address this issue directly, we
employed caveolin-1 gene knock-out mice that lack caveolin-1 protein expression and
caveolae organelles. Here, we show that endothelial cell caveolae are required for the
efficient uptake and transport of a known caveolar ligand, ie albumin, in vivo. Caveolin-1-null
mice were perfused with 5-nm gold-conjugated albumin, and its uptake was followed by …