Pesticide residues in food — 2007: Toxicological ... - ipcs inchem

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concentrations in females were found in rats at the highest dose only. Mild changes in a few bodyweight
adjusted organ weights did not follow a dose–response relationship and were therefore judged
to be incidental. Only the relative liver weights in females at the highest dose were higher than in
controls and showed a dose–response relationship (12.3 g at 1000 ppm and 10.5 g in the controls).
Although less pronounced, the same was found in the recovery groups (11.6 g at 1000 ppm and
10.7 g in the controls). On histopathology in males at the highest dose, an increased incidence (six
out of ten) of vacuolation of adrenal cells in the zona fasciculata was observed (two out of ten in
controls, zero out of ten in other groups) and focal vascular congestion in the mucosa of ileum was
found in both sexes (two out of ten in males and three out of ten in females, one out of ten in males
in the control group and zero out of ten in all other groups).
The NOAEL was 200 ppm, equal to 14.2 mg/kg bw per day, on the basis of liver-weight
increases in females at 1000 ppm (Ruckman, 1987).
Table 19. Changes in haematology parameters in male rats fed diets containing dimethomorph
for 13 weeks
Parameter Study groups Recovery groups
Dietary concentration (ppm)
0 40 200 1000 0 1000
Packed cell volume a (%) 51 51 51 49* 48 45***
Erythrocytes × 10 6 /mm 3 8.6 8.2 8.4 8.1* 8.0 7.7
Mean cell haemoglobin concentration (%) 30.1 29.8 30.6 31.2* 32.4 32.7
Lymphocytes × 10 3 /mm 3 12.43 11.42 12.08 9.15** 11.04 9.83
From Ruckman (1987)
a
Erythrocyte volume fraction.
* p ≤ 0.05; ** p ≤ 0.01; *** p ≤ 0.001.
Table 20. Histological findings in the ileum of rats and mice fed diets containing dimethomorph
Finding
Dietary concentration (ppm)
Males (n = 10) Females (n = 10)
0 2000 3000 4000 0 2000 3000 4000
Rats (Scott, 1986) 0 0 0 0 0 0 0 0
Dilatation 0 2 1 2 0 4 7 5
Inflammation 0 0 0 2 0 1 4 2
Serosa monocytes infiltrates 0 0 0 0 0 0 3 5
Mucosal hyperplasia 0 0 0 2 0 1 6 7
Fiber separation in muscle layer 0 0 0 0 0 1 5 6
Villous atrophy 0 2 2 1 1 0 1 1
Dietary concentration (ppm)
Males (n = 10) Females (n = 10)
0 800 2000/5000 300/10000 0 800 2000/4000 300/8000
Mice (Perry, 1986)
Dilatation 0 0 0 1 0 0 1 2
Villous atrophy 2 0 3 4 1 1 1 4
From Perry (1987) and Scott (1986)
DIMETHOMORPH 273–315 JMPR 2007