Table 1.
Cell-uptake (internalization + membrane-bound fractions) of the equimolar [99mTc]Tc-DT11+[99mTc]Tc-DB7 mixture during 1 h incubation at 37 °C in PC-3 cells, without or in the presence of excess GRPR or/and NTS1R blockers (non-specific), expressed as the average percentage of radioactivity added per well ± sd from three independent experiments performed in triplicate.
| Mixture 1 | +[Tyr4]BBN 2 | +NT 3 | +[Tyr4]BBN + NT | ||
|---|---|---|---|---|---|
| total/block | membrane-bound | 7.04 ± 0.55 | 1.63 ± 0.13 | 7.91 ± 0.39 | 1.50 ± 0.10 |
| internalized | 3.70 ± 0.33 | 2.73 ± 0.46 | 2.26 ± 0.13 | 1.17 ± 0.15 | |
| sum | 10.74 ± 0.61 | 4.36 ± 0.51 | 10.16 ± 0.45 | 2.67 ± 0.21 | |
| specific | membrane-bound | 5.54 ± 0.52 4 | 0.19 ± 0.15 5 | 6.40 ± 0.34 6 | - |
| internalized | 2.54 ± 0.32 | 1.68 ± 0.49 | 1.09 ± 0.26 | - | |
| sum | 8.08 ± 0.62 | 1.87 ± 0.56 | 7.49 ± 0.46 | - | |
1 Equimolar mixture of [99mTc]Tc-DT11+[99mTc]Tc-DB7; 2 radioligand mixture plus excess of [Tyr4]BBN added for GRPR-blockade; 3 radioligand mixture plus excess of NT added for NTS1R-blockade; 4 radioligand mixture plus excess of [Tyr4]BBN and NT combination added for parallel GRPR and NTS1R-blockade; 5,6 specific results determined for the [99mTc]Tc-DT11+[99mTc]Tc-DB7 mixture, and the partially blocked groups (either [Tyr4]BBN 5 or NT 6) are those calculated after subtraction of non-specific values during parallel GRPR and NTS1R-blockade from the respective total/partially blocked values.