Table 1

Formation of 32P postlabeled DNA adducts in liver and fat-free mammary epithelial cells of Sprague Dawley rats receiving a single dose of DMBA by gavage, according to various administration schedules

The effect of three chemopreventive agents was also investigated. See Fig. 1 <$REFLINK> for the identification of the five autoradiographic spots.
DMBA dose (mg/kg body weight)Time of sacrifice (days)aInhibitors (dietary dose)Organ or cellsDNA adducts/108 nucleotidesb
Spot 1Spot 2Spot 3Spot 4Spot 5Total
0Liver<0.1<0.1<0.1<0.1<0.1<0.1
Mammaryc<0.1<0.1<0.1<0.1<0.1<0.1
122Liver22.5 ± 7.18.4 ± 2.35.3 ± 2.32.6 ± 0.84.4 ± 2.443.2 ± 10.2
Mammary18.6 ± 6.53.8 ± 1.42.4 ± 1.31.7 ± 1.13.2 ± 1.929.7 ± 12.1
1225,6-BFLiver1.5 ± 0.7d<0.1d<0.1d<0.1d<0.1e1.5 ± 0.7d
(1650 ppm)Mammary2.7 ± 1.2d0.8 ± 0.8e0.4 ± 0.4f0.3 ± 0.2f0.6 ± 0.6f4.9 ± 3.0e
122BHALiver12.9 ± 1.6f4.6 ± 1.6f2.8 ± 1.00.9 ± 0.5e2.0 ± 1.623.2 ± 4.9e
(5000ppm)Mammary11.4 ± 6.53.4 ± 1.71.6 ± 0.51.2 ± 0.93.5 ± 1.421.1 ± 9.1
1221,2-D3TLiver8.7 ± 2.5e2.4 ± 1.6e1.7 ± 1.5f0.4 ± 0.4d0.4 ± 0.3e13.6 ± 5.9d
(600 ppm)Mammary8.3 ± 5.0f2.3 ± 0.81.1 ± 0.81.0 ± 0.62.2 ± 1.514.8 ± 7.6f
127Liver16.3 ± 6.33.4 ± 0.92.1 ± 0.80.8 ± 0.41.6 ± 0.824.2 ± 6.8
Mammary7.5 ± 2.82.4 ± 1.20.7 ± 0.71.1 ± 0.72.1 ± 0.713.9 ± 4.3
2.42Liver4.1 ± 2.02.2 ± 1.50.2 ± 0.40.2 ± 0.40.1 ± 0.26.8 ± 1.2
Mammary6.4 ± 2.72.1 ± 2.01.0 ± 1.00.8 ± 0.31.3 ± 0.611.6 ± 2.8
0.62Liver3.0 ± 2.70.2 ± 0.4<0.10.1 ± 0.2<0.13.3 ± 3.2
Mammary0.6 ± 0.30.3 ± 0.20.1 ± 0.10.2 ± 0.20.1 ± 0.21.2 ± 0.7
0.67Liver0.9 ± 0.5<0.10.02 ± 0.040.02 ± 0.040.06 ± 0.11.0 ± 0.5
Mammary0.3 ± 0.10.2 ± 0.20.1 ± 0.10.1 ± 0.2<0.10.7 ± 0.3
  • a After the last DMBA administration.

  • b DNA adduct levels are means ± SD of the results obtained in five rats, each analyzed in either duplicate (mammary cells) or triplicate (liver).

  • c Fat-free mammary epithelial cells.

  • d P < 0.001, as compared with the values recorded in rats receiving the same dose of DMBA, in the absence of chemopreventive agents.

  • e P < 0.01, as compared with the values recorded in rats receiving the same dose of DMBA, in the absence of chemopreventive agents.

  • f P < 0.05, as compared with the values recorded in rats receiving the same dose of DMBA, in the absence of chemopreventive agents.