Table 1

Tissue levels of radioactivity in pregnant mdr1b (+/+) and (−/−) mice 4 hr after i.v. injection of [3H]digoxin (1 mg/kg)

Tissuemdr1b (+/+)mdr1b (−/−)Ratio (−/−):(+/+)
Brain13.5 ± 2.418.7 ± 3.81.4
Muscle397 ± 47288 ± 240.7
Heart235 ± 55243 ± 181.0
Kidney319 ± 77361 ± 821.1
Liver727 ± 263766 ± 1191.1
Lung176 ± 56175 ± 141.0
Spleen118 ± 35120 ± 151.0
Colon604 ± 116574 ±1281.0
Uterus318 ± 89219 ± 600.7
Placenta322 ± 108258 ± 430.8
Fetuses105 ± 8109 ± 61.0
Plasma689 ± 343764 ± 811.1
  • Results are means ± SD in nanograms per gram tissue ([3H]digoxin equivalent). Three pregnant mice were analyzed in each group. All fetuses of each mother were pooled.