Table 2.
Tissue levels of radioactivity in female mdr1a/1b (+/+) and (−/−) mice 4 hr after i.v. injection of [3H]digoxin (1 mg/kg)
| Tissue | mdr1a/1b (+/+) | mdr1a/1b (−/−) | Ratio (−/−):(+/+) |
|---|---|---|---|
| Brain | 37.1 ± 5.6 | 1,011 ± 162 | 27.2** |
| Muscle | 329 ± 26 | 606 ± 134 | 1.8 |
| Heart | 245 ± 36 | 645 ± 98 | 2.6 |
| Kidney | 303 ± 30 | 774 ± 141 | 2.6 |
| Liver | 857 ± 116 | 2,180 ± 186 | 2.5 |
| Lung | 229 ± 10 | 603 ± 61 | 2.6 |
| Spleen | 131 ± 28 | 347 ± 61 | 2.6 |
| Thymus | 286 ± 65 | 792 ±134 | 2.8 |
| Lymph nodes | 167 ± 36 | 663 ± 158 | 3.9 |
| Adrenal gland | 500 ± 17 | 3,076 ± 979 | 6.2* |
| Uterus | 170 ± 13 | 379 ± 65 | 2.2 |
| Ovary | 545 ± 105 | 4,190 ± 474 | 7.7** |
| Plasma | 622 ± 73 | 1,775 ± 318 | 2.9 |
Results are means ± SD in nanograms per gram tissue ([3H]digoxin equivalent). Three mice were analyzed in each group. Asterisks: significantly increased in mdr1a/1b (−/−) mice after normalization for the increased plasma levels. *P < 0.05; **P < 0.002.