Pesticide residues in food — 2006: Toxicological ... - ipcs inchem

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“Ground glass” hepatocytes 07 0/5 0/6 7/7 07 0/5 0/6 7/7
Hepatocyte cytoplasmic inclusions 0/7 0/5 0/6 1/7 0/7 0/7 0/7 0/7
Increased mitotic figures (liver) 0/7 0/5 0/6 4/7 0/7 0/5 0/6 4/7
Thyroid follicular hypertrophy 0/7 0/5 0/6 2/7 0/7 0/5 0/6 1/7
From Porter et al. (1995)
* p < 0.05; ** p < 0.01.
Table 29. Findings related to reproductive toxicity in a range-finding study in female rats fed
diets containing thiacloprid
Finding
Dietary concentration (ppm)
0 100 400 1600
Mating index 100 100 100 100
Fertility index 100 71.4 85.7 100
Gestation index 100 100 100 100
No. of litters 7 5 6 7
Total No. of pups born 107 73 81 97
Litter size, mean 15.3 14.6 13.5 13.9
No. of stillborn pups (%) 6 (5.6) 1 (1.4) 1 (1.2) 3 (3.1)
Live birth index (%) 95.0 98.8 99.0 96.8
Total No. of dead pups (%) 9 (8.4) 3 (4.1) 1 (1.2) 21* (21.6)
Pup deaths (day 0–4) 3 2 0 16
Viability index (%) 96.4 97.4 100.0 83.9
Pup deaths (days 5–21) 0 0 0 2
Weaning index, mean 100 100 100 96.4
Mean weight of viable pups (g), birth 6.0 6.3 6.6 6.0
Day 4 9.8 10.4 10.4 8.1*
Day 11 26.0 27.5 26.6 19.3**
Day 21 56.1 57.1 53.6 41.0**
Day 28 93.3 92.7 90.2 66.8**
Day 35 141.8 140.2 133.7 104.0**
Body-weight gain (g) 135.8 133.8 127.1 98.1**
From Porter et al., (1995)
* p < 0.05; ** p < 0.01.
Histopathological effects in the liver (hepatocyte hypertrophy, “ground glass” appearance of
hepatocyte cytoplasm, hepatocyte glycogenic vacuolar change) were seen at 1600 ppm and in one
F 0
female at 400 ppm. Thyroid follicular cell hypertrophy was also noted at 1600 ppm and in one F 0
male at 400 ppm. Similar findings were noted in F 0
and F 1
animals.
No treatment-related effects on reproductive performance were seen. The number of pup deaths
(days 0–4) was significantly increased at 1600 ppm, resulting in a slightly lower viability index for
this dose group. Mean pup weight at 1600 ppm was significantly lower from day 4, pup weights at
birth were comparable in all dose groups (Table 29).
The NOAEL for parental toxicity was 400 ppm, equivalent to about 27 mg/kg bw per day, on
the basis of microscopic hepatic and thyroid changes in F 0
and F 1
animals at 1600 ppm. The NOAEL
for reproductive toxicity was 400 ppm, equivalent to about 27 mg/kg bw per day, on the basis of
decreased body-weight gain and survival in pups at 1600 ppm (Porter et al., 1995).
THIACLOPRID X-X JMPR 2006