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

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Observations during handling
Dilated pupils 0 0 0 9* 0 0 4* 11*
Open fi eld observations
Tremors:
Slight 0 3 6* 0 0 0 3* 0
Moderate to severe 0 0 0 12* 0 0 0 12*
Gait incoordination:
Slight 0 0 0 9* 0 0 0 8*
Moderate to severe 0 0 0 0 0 0 0 2*
Ptosis of eyelids 0 1+ 1+ 7+ 0 0 0 10+
Refl ex/physiological observations
Approach response:
No reaction 1 4 6* 10* 0 1 3* 11*
Slight reaction 11 8 6* 2* 12 11 9* 1*
Righting response:
Slight incoordination 0 0 1 5* 0 1 1 9*
Landing on side 0 0 0 0 0 0 0 1*
Body temperature (°C) 36.6 36.7 36.6 32.3* 36.9 36.2 36.3 30.1*
From Sheets et al. (1997)
* p < 0.05; + not subjected to statistical analysis.
There were no deaths at any dose before scheduled terminal sacrifice. Clinical signs observed
in both sexes after the highest dose were tremor, decreased activity, locomotor incoordination
(ataxia), cool-to-touch body, dilated pupils, urine staining and eyelid ptosis. Further signs in females
at the highest dose were red nasal and oral staining, clear nasal discharge, and clear lacrimation.
At 53 mg/kg bw, only dilated pupils were seen in one female. The clinical signs occurred only on
the day of treatment and were typically resolved by day 1, at the latest by day 4. Body weights were
slightly reduced by treatment in males at the highest dose only.
In the FOB, compound-related effects were evident at the time of peak neurobehavioural effects
on day 0 in males and females after all three doses (Table 36). Evidence of toxicity increased with
dose, with minimal effects evident in only a few animals that received the lowest dose of 22 mg/kg
bw and severe toxicity evident in all animals that received the highest dose of 109 mg/kg bw. To a
large extent, the spurious difference in toxicity between the FOB and clinical observations reflects
the rapid recovery after treatment, as clinical observations were performed some hours after the FOB
and motor activity. All signs of toxicity resolved in all dosed groups by the next observation period
on day 7.
Treatment-related decreases in motor and locomotor activity in the figure-eight maze were
observed on day 0 in males at 109 mg/kg bw, and in females at all doses tested (Table 37). All signs
were completely reversible in males and females by the next test occasion, 7 days after treatment.
Habituation was not affected by treatment with thiacloprid.
THIACLOPRID X-X JMPR 2006