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Toxicological information

Repeated dose toxicity: oral

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Administrative data

Endpoint:
sub-chronic toxicity: oral
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Comparable to Guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2003
Report Date:
2003

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 408 (Repeated Dose 90-Day Oral Toxicity in Rodents)
Deviations:
yes
Principles of method if other than guideline:
Range-finding study: Only limited histopathology performed and no special neurotoxicity examination included
GLP compliance:
no
Remarks:
no GLP required (range-finding study for long-term toxicity)
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
other: liquid
Details on test material:
Name of test material (as cited in study report): ATBC
Substance type: pure active
Physical state: liquid

Test animals

Species:
rat
Strain:
Wistar
Sex:
male/female

Administration / exposure

Route of administration:
oral: feed
Vehicle:
unchanged (no vehicle)
Analytical verification of doses or concentrations:
yes
Duration of treatment / exposure:
13 weeks
Frequency of treatment:
Daily via the diet
Doses / concentrations
Remarks:
Doses / Concentrations:
0, 96.02, 287.50 and 961.16 mg/kg
Basis:
actual ingested
No. of animals per sex per dose:
10 m / 10 f
Control animals:
yes, plain diet

Examinations

Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: Yes
Observation for mortality/viability were recorded twice daily

DETAILED CLINICAL OBSERVATIONS: Yes
Time schedule: At least once daily. Palpation for tissue masses were performed at least once weekly

BODY WEIGHT: Yes
Time schedule for examinations: Weekly during pre-test, treatment and before necropsy

FOOD CONSUMPTION AND COMPOUND INTAKE:
Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day

FOOD EFFICIENCY: no

WATER CONSUMPTION AND COMPOUND INTAKE: no

OPHTHALMOSCOPIC EXAMINATION: Yes
Time schedule for examinations: During acclimatization and during week 13
Dose groups that were examined: All groups during acclimatization and all animals of the control and high dose group during week 13

HAEMATOLOGY: Yes
Time schedule for collection of blood: week 13 weeks
Anaesthetic used for blood collection: yes (light isoflurane anaesthesia)
Animals fasted: Yes
How many animals: all (10 m / 10 f per group)
Parameters examined: Erythrocyte count, haemoglobin, haematocrit, MCV, RDW, MCH, MCHC, HDW, reticulocyte, reticulocyte maturity index, leukocyte count, differential leukocyte count, prothrombin time, partial thromboplastin time

CLINICAL CHEMISTRY: Yes
Time schedule for collection of blood: week 13
Animals fasted: Yes
How many animals: all (10 m / 10 f per group)
Parameters examined: Glucose, urea, creatinine, bilirubin (total), cholesterol, tryglicerides, phospholipides, ASAT, ALAT, LDH, CK, ALP, GGT, Sodium, potassium, chloride, calcium, inorganic phosphorus, protein (total), albumin, globulin, albumin/globulin ration

URINALYSIS: no

NEUROBEHAVIOURAL EXAMINATION: no
Sacrifice and pathology:
GROSS PATHOLOGY: Yes, all organs, all groups
HISTOPATHOLOGY: Yes.
Statistics:
Dunnett-test (many to one t-test) based on a pooled variance estimate if variables can be assumed to follow a normal distribution
Steel-test (many-one rank test) was applied instead of the Dunnett-test when data were not assumed to follow a normal distribution
Fisher's exact test was applied for ophthalmoscopic data and macroscopic findings
Armitage/Cochran Trend Test was used for non-neoplastic lesions, if appropriate

Results and discussion

Results of examinations

Clinical signs:
no effects observed
Mortality:
no mortality observed
Body weight and weight changes:
no effects observed
Food consumption and compound intake (if feeding study):
no effects observed
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
no effects observed
Haematological findings:
no effects observed
Clinical biochemistry findings:
effects observed, treatment-related
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Gross pathological findings:
effects observed, treatment-related
Histopathological findings: non-neoplastic:
effects observed, treatment-related
Histopathological findings: neoplastic:
no effects observed
Details on results:
CLINICAL CHEMISTRY
In m and f at 1000 mg/kg bw/day, decreased bilirubin levels, decreased aspartate aminotransferase and lactate dehydrogenase activity, increased sodium level, decreased chloride and calcium levels, decreased globulin levels (which resulted in increased albumin/globulin ratio) were evident in m at 300 and 1000 mg/kg bw/d

ORGAN WEIGHTS
1000 mg/kg: increased liver weights in m and f

GROSS PATHOLOGY
1000 mg/kg: enlarged livers in 2 f

HISTOPATHOLOGY: NON-NEOPLASTIC
1000 mg/kg: minimal hepatocellular hypertrophy (non-adverse) in several animals

Effect levels

Dose descriptor:
NOAEL
Remarks:
1000 mg/kg bw/day
Effect level:
>= 1 000
Sex:
male/female
Basis for effect level:
other: see 'Remark'

Target system / organ toxicity

Critical effects observed:
not specified

Any other information on results incl. tables

Table: Summary of test item-related findings for ATBC

 

Intended test item intake (mg/kg bw/day)

0

100

300

1000

 

 

 

 

 

Clinical chemistry

Males (means)

 

 

 

 

Glucose (mmol/L)

4.886

6.124**

5.895**

5.784*

Bilirubin (µmol/L)

2.055

1.955

1.767

1.305**

ASAT (U/L)

82.37

76.37

71.90**

66.08**

LDH (U/L)

136.50

120.88

92.29**

91.27**

Sodium (mmol/L)

144.58

145.00

154.52**

153.72**

Chloride (mmol/L)

100.94

101.33

89.18**

89.25**

Calcium (mmol/L)

2.834

2.811

2.666**

2.694**

Globulin (g/L)

26.356

26.474

24.431**

24.123**

Alb/Glob ratio (rel., %)

1.590

1.640

1.727*

1.755**

 

 

 

 

 

Females (means)

 

 

 

 

Bilirubin (µmol/L)

2.795

2.346

2.057

1.642**

 

 

 

 

 

Organ weights

Liver (means)

 

 

 

 

Males (abs., gram)

8.83

9.30

9.58

10.86**

Males (rel., %)

2.34

2.38

2.51

2.86**

 

 

 

 

 

Females (abs., gram

5.88

6.12

5.80

7.10**

Females (rel., %)

2.65

2.71

2.76

3.03*

 

 

 

 

 

Macroscopic findings

Liver (no. affected/10)

0/10

0/10

0/10

2/10

Females: Enlarged

 

 

 

 

Histopathology

Liver (no. affected/10)

 

 

 

 

Males: Hepatocellular hypertrophy

1/10

0/10

6/10

5/10

Females: Hepatocellular hypertrophy

0/10

0/10

1/10

2/10

 

  • * = 5% level (Anova and/or Dunnett-Test)
  • ** = 1% level (Anova and/or Dunnett-Test)

 

Applicant's summary and conclusion

Conclusions:
Based on the results of this study, dose levels of 100, 300 and 1000 mg/kg bw/d were proposed for the subsequent 2-year combined chronic/carcinogenicity study. Slight effects seen at 1000 mg/kg bw/d were considered due to hepatic metabolism adaption. Thus the NOAEL for m and f in this study was given with 1000 mg/kg bw/d.
Executive summary:

This 13-weeks dietary toxicity study with acetyl tributyl citrate (ATBC) in Wistar rats was designed as dose range finding study for a subsequent combined chronic/carcinogenicity study. In principle, the study was performed according to OECD Guideline 408, but with restricted histopathological organ examinations. The administration at target doses of 100, 300 and 1000 mg/kg bw/d resulted in no unscheduled deaths. No test item-related clinical signs were observed. Treatment-related findings were restricted to slight changes in clinical biochemistry (males were more affected than females) and slightly increased liver weights accompanied by minimal hepatocellular hypertrophy at 1000 mg/kg bw/d. The findings were considered to be due to hepatic metabolic adaption rather than as sign of toxicity. The highest dose of 1000 mg/kg bw can be regarded as NOAEL. The proposed dose levels for a subsequent combined chronic/carcinogenicity study were 100, 300 and 1000 mg/kg bw/d. It can be assumed that the same applies to tris(2-ethylhexyl) 2-(acetyloxy)propane-1,2,3-tricarboxylate (CAS 144 -15 -0) as it is a near analogue to the test substance acetyl tributyl citrate.