TABLE 2.

Perinatal exposure to 250 ng/kg·d alters the sensitivity to estradiol in the mammary glands of ovariectomized animals

	A.0BPA/0E2 (mean ± sem)	B.0BPA/0.5E2 (mean ± sem)	P (A and B)	C.250BPA/0E2 (mean ± sem)	D.250BPA/0.5E2 (mean ± sem)	P (C and D)	P (B and D)
No. of TEBs	1.4 ± 0.58119	5.5 ± 1.16667	0.004	2.09091 ± 0.77991	10 ± 0.64979	0.000	0.007
TEB area	0.048 ± 0.0201	0.219 ± 0.05374	0.007	0.07818 ± 0.02885	0.428 ± 0.0396	0.000	0.005
Ductal extension	2.6155 ± 0.62599	4.41091 ± 0.74227	ns	2.80273 ± 0.7631	4.686364 ± 0.5776	0.016	ns
Ductal area	79.081 ± 8.65917	126.135 ± 9.20329	0.002	82.2555 ± 6.96275	118.5518 ± 8.21476	0.005	ns
TEB size	0.0137 ± 0.00559	0.03384 ± 0.0043	0.023	0.02021 ± 0.00599	0.04228 ± 0.00164	0.000	ns
No. of TEBs/area	0.0146 ± 0.00622	0.04195 ± 0.00896	0.029	0.02289 ± 0.00599	0.084893 ± 0.00621	0.000	0.003
TEB area/area	0.0005 ± 0.00021	0.00167 ± 0.00041	0.019	0.00086 ± 0.0003	0.003576 ± 0.00029	0.000	0.004

Animals exposed perinatally to 250 ng BPA/kg bw·d or to vehicle were ovariectomized at 25 d of age and implanted with osmotic pumps delivering 0 or 0.5 μg estradiol/kg bw·d from 25–35 d of age. A, Perinatal treatment with vehicle and implanted with pumps delivering vehicle at 25–35 d old; B, perinatal treatment with vehicle and implanted with pumps delivering 0.5 μg estradiol/kg bw·d at 25–35 d old; C, perinatal treatment with 250 ng BPA/kg bw·d and implanted with pumps delivering vehicle at 25–35 d old; D, perinatal treatment with 250 ng BPA/kg bw·d and implanted with pumps delivering 0.5 μg E₂/kg bw·d at 25–35 d old. P (A and B) denotes the P value of the comparison between groups A and B; P (C and D) denotes the P value of the comparison between groups C and D; and P (B and D) denotes the P value of the comparison between groups B and D. ns, Lack of statistically significant differences. No. of TEBs denotes number of TEBs at the leading edge of the 4th mammary gland; ductal area is expressed in mm². Ductal extension denotes the distance from the center of the lymph node to the leading edge in mm; TEB size is expressed in mm². TEBs/area denotes the number of TEBs relative to the ductal area; it is expressed as number/mm², and TEB area/area denotes the area (mm²) occupied by the TEBs relative to the total area (mm²) of the ductal tree. There were no statistically significant differences between the mice treated perinatally with 0 and 250 ng BPA/kg bw·d after ovariectomy for any of the parameters measured (groups A and C).