Ex vivo biodistribution of 68Ga-DOTA-peptide in VAP-1–positive wild-type mice and VAP-1–negative KO mice bearing melanoma xenografts
| . | WT 60 min . | WT 60 min + competition . | KO 60 min . |
|---|---|---|---|
| Blood | 1.04 ± 0.44* | 0.20 ± 0.02 | 0.25 ± 0.01 |
| Kidney | 5.10 ± 0.86 | 6.39 ± 1.19 | 7.78 ± 1.47 |
| Liver | 1.82 ± 0.25 | 0.74 ± 0.08 | 0.97 ± 0.07 |
| Lung | 0.69 ± 0.21 | 0.15 ± 0.01 | 0.02 ± 0.00 |
| Muscle | 0.21 ± 0.07 | 0.03 ± 0.00 | 0.04 ± 0.01 |
| Small intestine | 0.59 ± 0.16 | 0.10 ± 0.03 | 0.08 ± 0.01 |
| Tumor | 0.56 ± 0.12 | 0.17 ± 0.02 | 0.20 ± 0.02 |
| . | WT 60 min . | WT 60 min + competition . | KO 60 min . |
|---|---|---|---|
| Blood | 1.04 ± 0.44* | 0.20 ± 0.02 | 0.25 ± 0.01 |
| Kidney | 5.10 ± 0.86 | 6.39 ± 1.19 | 7.78 ± 1.47 |
| Liver | 1.82 ± 0.25 | 0.74 ± 0.08 | 0.97 ± 0.07 |
| Lung | 0.69 ± 0.21 | 0.15 ± 0.01 | 0.02 ± 0.00 |
| Muscle | 0.21 ± 0.07 | 0.03 ± 0.00 | 0.04 ± 0.01 |
| Small intestine | 0.59 ± 0.16 | 0.10 ± 0.03 | 0.08 ± 0.01 |
| Tumor | 0.56 ± 0.12 | 0.17 ± 0.02 | 0.20 ± 0.02 |
Results are expressed as standardized uptake values (mean ± SD; WT, n = 3; WT + peptide competition, n = 3; and KO, n = 2). Competition was done by injecting 500-fold molar excess of unlabeled DOTA-peptide along with 68Ga-DOTA-peptide.
WT indicates VAP-1–positive wild-type mice; and KO, VAP-1–negative knock-out mice.
The relatively high level of radioactivity in the blood of WT mice is the result of the soluble, enzymatically active VAP-1 in serum.