Uptake of 99mTc-Labeled Derivatives in Mouse Liver After Treatment with Cycloheximide*
| Protein | Binding affinity (pK) | Mean %ID in liver (untreated) ± SD (n) | Mean %ID in liver (cycloheximide treated) ± SD (n) | Difference (treated – control) | SEM of difference | Ratio for treated mice to control mice |
|---|---|---|---|---|---|---|
| Annexin V-128 | 30.8 ± 1.0 | 5.3 ± 3.37 (19) | 14.6 ± 6.82 (21) | 9.29† | 1.72 | 2.77 |
| 99mTc-MAG3-annexin V | 23.1 ± 2.1 | 7.1 ± 2.37 (15) | 11.9 ± 3.30 (15) | 4.76† | 1.09 | 1.67 |
| 99mTc-HYNIC-annexin V | 21.3 ± 2.2 | 7.2 ± 0.67 (6) | 11.7 ± 1.55 (6) | 4.53† | 0.76 | 1.63 |
| Biotin-99mTc-HYNIC-annexin V | 19.7 | 7.5 ± 0.53 (5) | 12.2 ± 2.24 (6) | 4.70† | 1.04 | 1.63 |
| Annexin V-131 | 22.4 ± 1.5 | 2.8 ± 0.07 (4) | 5.7 ± 1.02 (4) | 2.85† | 0.59 | 2.01 |
| Annexin V-138 | 22.4 ± 1.5 | 4.1 ± 0.67 (4) | 6.1 ± 3.25 (5) | 2.00 | 1.67 | 1.49 |
| Annexin V-136 | 13.9 ± 1.2 | 3.2 ± 0.29 (4) | 2.8 ± 0.46 (4) | −0.41 | 0.31 | 0.87 |
| Annexin V-139 | 15.8 ± 1.2 | 1.2 ± 0.33 (5) | 1.7 ± 0.32 (5) | 0.48 | 0.23 | 1.39 |
↵* Mice received either cycloheximide (50 mg/kg intraperitoneally) or no treatment. Two hours later, radiolabeled protein was injected via tail vein. One hour after injection of tracer, animals were sacrificed, and their organs were harvested. Annexin V-128, annexin V-131, annexin V-138, annexin V-136, and annexin V-139 were all labeled via single endogenous peptide chelation site at N terminus. 99mTc-HYNIC-annexin V contained 0.5 mol of 99mTc-HYNIC per mole of protein; derivatization level was not determined for other 2 proteins. Sources for pK values were as follows: annexin V-128 (20,24); 99mTc-MAG3-annexin V and 99mTc-HYNIC-annexin V (21) (reprinted with permission from Elsevier); biotin-99mTc-HYNIC-annexin V (this study); and annexin V-131, annexin V-138, annexin V-136, and annexin V-139 (20). Animal data for annexin V-131, annexin V-138, annexin V-136, and annexin V-139 were from Tait et al. (20). Biodistributions of all of these radiolabeled proteins in other organs, except for biotin-99mTc-HYNIC-annexin V, were described previously (20,21,37).
↵† Difference between treated and control animals was statistically significant (P < 0.01, as determined by 2-tailed t test with unequal variances).