Figure 3.

Binding pattern of Om-Au. (A) When Om-Au (≈22 nm diameter) was perfused as in Fig. 2 A–C, the necks of many caveolae opened to the lumina (v₁) were plugged by the tracer. (Bar = 49 nm.) (B) By 15 min of perfusion, the gold coated particles are seen plugging the necks of the caveolae (v₃) opened on the abluminal front of the cells. Not so often, the necks of some caveolae (v₃) opened on the tissular side of endothelial cells are plugged with two gold particles. (Bar = 28 nm.) l, lumen; pcs, pericapillary space(s); the same abbreviations are used for Fig. 4.