Table IV.
Gestation, lactation and developmental parameters of dams and offspring exposed to Printex 90 by inhalation or intratracheal instillation and control mice.
| Inhalation | Instillation | |||||
|---|---|---|---|---|---|---|
| Control | Printex 90 41.7 mg/m3 ∼ 287 mg/animal | Control | Printex 90 11 mg/animal | Printex 90 54 mg/animal | Printex 90 268 mg/animal | |
| Time mated/exposure groups | 22 | 22 | 24 | 17 | 17 | 22 |
| Dam arrival weight, GD 4 (g) | 22.21 ± 1.47 | 21.82 ± 1.27 | 23.01 ± 1.33 | 22.37 ± 1.20 | 22.59 ± 1.03 | 22.87 ± 0.89 |
| Number of litters PND 1 | 18 | 17 | 20 (−1†) | 10 (−4†) | 11 (−2†) | 20 |
| Dam weight gain, GD 7–18 (g)‡ | 11.25 ± 0.58 | 10.64 ± 0.71 | 11.94 ± 0.33 | 12.00 ± 0.73 | 11.00 ± 0.61 | 10.79 ± 0.36 |
| Dam lactation weight gain PND 1(2)–17 (g) | 4.31 ± 0.27 | 4.34 ± 0.41 | 4.40 ± 0.43 | 4.38 ± 0.81 | 4.85 ± 0.45 | 4.93 ± 0.46 |
| Gestation length (days) | 19.89 ± 0.07 | 20.06 ± 0.06 | 20.00 ± 0.00 | 20.00 ± 0.00 | 20.09 ± 0.09 | 20.05 ± 0.05 |
| Implantations | 7.39 ± 0.56 | 7.59 ± 0.54 | 9.25 ± 0.21 | 9.27 ± 0.57 | 8.08 ± 0.62 | 8.32 ± 0.46 |
| Implantation loss (%) | 14.59 ± 3.88 | 17.01 ± 4.57 | 21.52 ± 2.52 | 30.74 ± 8.42 | 25.61 ± 7.75 | 24.16 ± 3.70 |
| Live pups per litter PND 1 | 5.09 ± 0.91 | 4.95 ± 0.74 | 7.30 ± 0.34 | 7.00 ± 0.67 | 6.82 ± 0.52 | 6.20 ± 0.34 |
| Offspring dead during lactation (%) | 4.10 ± 1.98 | 1.72 ± 1.19 | 5.49 ± 2.06 | 10.00 ± 10.00 | 1.30 ± 1.30 | 3.26 ± 1.94 |
| Birth weight females (g) | 1.40 ± 0.04 | 1.41 ± 0.05 | 1.33 ± 0.03 | 1.30 ± 0.03 | 1.31 ± 0.04 | 1.30 ± 0.03 |
| Birth weight males (g) | 1.43 ± 0.03 | 1.42 ± 0.05 | 1.35 ± 0.02 | 1.38 ± 0.04 | 1.36 ± 0.04 | 1.35 ± 0.04 |
| Weight gain females PND 1(2)–22 (g) | 8.02 ± 0.23 | 7.66 ± 0.32 | 6.37 ± 0.29 | 7.34 ± 0.47 | 6.96 ± 0.45 | 7.50 ± 0.29 |
| Weight gain males PND 1(2)–22 (g) | 8.28 ± 0.18 | 7.89 ± 0.38 | 7.12 ± 0.32 | 7.33 ± 0.62 | 7.86 ± 0.60 | 7.86 ± 0.24 |
| Sex ratio§ | 0.42 ± 0.06 | 0.51 ± 0.06 | 0.46 ± 0.04 | 0.66 ± 0.06 | 0.56 ± 0.06 | 0.45 ± 0.04 |
GD, gestation day (pregnancy day); PND, post natal day (days after birth). Dams were allowed to deliver their offspring on gestation day (GD) 20, equal to post natal day (PND) 0. Weights of dams and individual offspring were recorded on PND 2 (1), and offspring were counted and sex determined. Time mated mice were examined for the number of implantation sites, allowing for calculation of implantation loss. Females that did not give birth or had small litters were killed on PND 3 (1–2) and the dams on PND 22–23 (24–25). Data are expressed as mean ± SEM, offspring data are calculated as litter average.
Died during instillation.
Weight before exposure.
Females in litter (%).