Table 3.

Lysosomal accumulation of uPAR in nonpolarized MDCK cells preloaded with cationized 20-nm colloidal gold and chased in the presence of 100 nM DFPuPA or uPA:PAI-1 for 3 h

Ligand	Plasma membrane (%)	Compartments with <4 20-nm gold particles (%)	Compartments with at least 4 20 nm gold particles (%)	Total uPAR gold particle count	No. of cell profiles counted
DFP-uPA	74.8  ± 11.6	23.1  ± 9.8	1.1  ± 0.1	2286  (n = 3)	21
uPA/PAI	58.6  ± 8.6	31.6  ± 6.7	9.85  ± 1.9	1339  (n = 2)	16

Cryosections were single labeled with anti-uPAR antibodies followed by 10 nm gold-conjugated protein A, and distribution of labeling on plasma membrane or in endocytic compartments containing either less than four dispersed or more than four, mostly aggregated, 20-nm gold particles was determined.