Target-to-Muscle and Target-to-Blood Ratios of 99mTc(I)-Estradiol-Pyridin-2-yl Hydrazine Derivative
| Ratio at the following time (h) after injection: | ||||
|---|---|---|---|---|
| Target-to-background | 1 | 3 | 3 (block)* | 24 |
| Uterus-to-muscle | 6.44 ± 0.81 | 5.21 ± 1.12 | 3.32 ± 0.46 | 3.58 ± 0.47 |
| Mammary gland-to-muscle | 7.05 ± 0.87 | 6.74 ± 1.21 | 2.45 ± 0.51 | 3.50 ± 0.82 |
| MCF-7 tumor-to-muscle | 4.75 ± 0.43 | 5.67 ± 1.06 | 2.64 ± 0.53 | 3.54 ± 0.26 |
| Uterus-to-blood | 0.57 ± 0.02 | 0.34 ± 0.04 | 0.24 ± 0.02 | 1.02 ± 0.16 |
| Mammary gland-to-blood | 0.62 ± 0.05 | 0.43 ± 0.05 | 0.18 ± 0.02 | 0.91 ± 0.11 |
| MCF-7 tumor-to-blood | 0.43 ± 0.07 | 0.35 ± 0.05 | 0.19 ± 0.02 | 1.03 ± 0.19 |
↵* Receptor blocking studies were performed by coinjecting 5 μg of 17β-estradiol with radiotracer. All ratios at 3 h after injection were significantly different (P < 0.05) from ratios at 3 h after injection when radiotracer was coinjected with 5 μg of 17β-estradiol to block receptor.
99mTc(I)-estradiol-pyridin-2-yl hydrazine uptake was determined in ovariectomized female athymic NCr-nu/nu mice bearing MCF-7 human breast adenocarcinoma tumors. Data represent mean ± SEM from at least 4 determinations.