Table 1.

PECAM-1-targeted pulmonary accumulation of antioxidant enzymes after i.v. injection in mice

Treatment	Blood (% ID/g)	Lung (% ID/g)	Lung/blood ratio
Catalase	5.0 ± 0.9	2.7 ± 0.6	0.6
PEG-catalase	20.0 ± 12.0	4.0 ± 1.3	0.2
Anti-PECAM/catalase
WT	6.6 ± 0.5*	84.3 ± 14.3**	12.8
KO	20.8 ± 1.1	9.7 ± 0.7	0.5
Anti-PECAM/SOD	6.3 ± 0.6#	63.1 ± 13.5##	10.0
IgG/SOD	10.4 ± 1.1	6.1 ± 1.2	0.6

Catalase and SOD conjugated with PECAM, control nonimmune IgG, or PEG or in their native unconjugated form were injected into mice via tail vein. Animals were sacrificed after 1 h, and tissue distribution of antioxidant enzymes was analyzed by tracing ¹²⁵I-labeled catalase or SOD. % ID, percentage of injected dose; WT, normal wild-type C-57BL/65 mice; KO, PECAM-knockout mice (target negative control). Values are means ± sd.

^*P < 0.01,

^**P < 0.001 vs. KO;

^#P < 0.01,

^##P < 0.001 vs. IgG/SOD.