Registration Dossier

Administrative data

Endpoint:
developmental toxicity
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1990-05-25 to 1990-08-17
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1991
Report Date:
1991

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 414 (Prenatal Developmental Toxicity Study)
GLP compliance:
yes (incl. certificate)
Remarks:
preinspection, according to §19b German Chemicals Act
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
liquid
Details on test material:
- Name of test material (as cited in study report): Tri-n-butylamine
- Physical state: colourless liquid
- Analytical purity: 99.3 %
- Purity test date: 1989-03-08
- Lot/batch No.: 470811, Code No. HOE CG 0113 OA ZD 99 001
- Storage condition of test material: at room temperature

Test animals

Species:
rat
Strain:
Sprague-Dawley
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Lippische Versuchstierzucht Hagemann, Extertal, Germany
- Age at study initiation: sexually mature
- Weight at study initiation: 192-245 g
- Housing: individually, for mating with male rat of the same breed
- Diet (ad libitum): Altromin 1314, Altromin, Lage, Lippe, Germany
- Water (ad libitum): tap water


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 2
- Humidity (%): 50 +/- 10
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
other: 1% aqueous hydroxypropyl-methylcellulose gel
Details on exposure:
PREPARATION OF DOSING SOLUTIONS:
freshly each day immediately before administration

VEHICLE
- Amount of vehicle (if gavage): 5 ml/kg
- Lot/batch no. (if required): MM 84072811
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Examination on homogenicity and stability: extraction of the test substance with methanol, analysis with GC/FID
Details on mating procedure:
- Impregnation procedure: cohoused
- If cohoused:
- M/F ratio per cage: 1/1
- Length of cohabitation: one dark period
- Further matings after two unsuccessful attempts: no, replacement by other animal
- Verification of same strain and source of both sexes: yes
- Proof of pregnancy: sperm in vaginal smear referred to as day 0 of pregnancy
Duration of treatment / exposure:
gd 6 - 15
Frequency of treatment:
1x/d
Duration of test:
10 days
Doses / concentrationsopen allclose all
Dose / conc.:
0 mg/kg bw/day (actual dose received)
Dose / conc.:
15 mg/kg bw/day (actual dose received)
Dose / conc.:
45 mg/kg bw/day (actual dose received)
Dose / conc.:
135 mg/kg bw/day (actual dose received)
No. of animals per sex per dose:
20 females
Control animals:
yes, concurrent vehicle
Details on study design:
- Dose selection rationale: pretest with 10, 30, 100, 300, 600 and 900 mg/kg bw/day, lethal effects at 300 mg/kg bw/day and above

Examinations

Maternal examinations:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice daily (morning/evening)

DETAILED CLINICAL OBSERVATIONS: No


BODY WEIGHT: Yes
- Time schedule for examinations: daily


POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day 20
- Organs examined: ovaries and uterus (corporea lutea, implantations), dissection with macroscopic examination of internal organs


OTHER: food and water consumption monitored daily
Ovaries and uterine content:
The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: No data
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: No data
- Number of late resorptions: No data
Fetal examinations:
- External examinations: Yes: all per litter
- Soft tissue examinations: Yes: half per litter
- Skeletal examinations: Yes: half per litter
- Head examinations: No
Statistics:
The Student's t-test was used for statistical analysis

Results and discussion

Results: maternal animals

General toxicity (maternal animals)

Clinical signs:
no effects observed
Dermal irritation (if dermal study):
not examined
Mortality:
mortality observed, treatment-related
Description (incidence):
3 females of high dose group died between GD 7 and 8
Body weight and weight changes:
effects observed, treatment-related
Description (incidence and severity):
body weight of the animals of the high dose group stagnated on the first two days of test item application, but returned thereafter to normal
Food consumption and compound intake (if feeding study):
effects observed, treatment-related
Description (incidence and severity):
reduced food consumption in the highest dose group (up to a maximum of 18% reduction in comparison to controls on GD 8), which returned to normal on GD 11
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
no effects observed
Ophthalmological findings:
not examined
Haematological findings:
not examined
Clinical biochemistry findings:
not examined
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Immunological findings:
not examined
Organ weight findings including organ / body weight ratios:
no effects observed
Gross pathological findings:
effects observed, treatment-related
Description (incidence and severity):
red discolorated lungs in the 3 animals of high dose group which died
Neuropathological findings:
not examined
Histopathological findings: non-neoplastic:
not examined
Histopathological findings: neoplastic:
not examined
Other effects:
not specified
Details on results:
No adverse effects were observed of the dams of the low and mid dose group. Three animals of the high dose group died which showed red discoloration of the lungs at necropsy.

Maternal developmental toxicity

Number of abortions:
no effects observed
Pre- and post-implantation loss:
no effects observed
Total litter losses by resorption:
no effects observed
Early or late resorptions:
no effects observed
Dead fetuses:
no effects observed
Changes in pregnancy duration:
not examined
Description (incidence and severity):
Migrated Data from removed field(s)
Field "Effects on pregnancy duration" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsMaternalAnimals.MaternalDevelopmentalToxicity.EffectsOnPregnancyDuration): not examined
Changes in number of pregnant:
no effects observed
Details on maternal toxic effects:
Maternal toxic effects:yes

Details on maternal toxic effects:
Effects were noted only in the high-dose group:
-Transiently reduced food consumption and body weight gain after start of dosing
3 dams died prematurely (day 7 and 8). These animals showed red discoloration of the lungs.

Effect levels (maternal animals)

Key result
Dose descriptor:
NOAEL
Effect level:
45 mg/kg bw/day
Basis for effect level:
other: maternal toxicity

Maternal abnormalities

Key result
Abnormalities:
no effects observed
Description (incidence and severity):
no effects observed except mortality and transient reduction of food consumption and body weight gain

Results (fetuses)

Fetal body weight changes:
no effects observed
Description (incidence and severity):
Migrated Data from removed field(s)
Field "Fetal/pup body weight changes" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsFetuses.FetalPupBodyWeightChanges): not examined
Reduction in number of live offspring:
no effects observed
Changes in sex ratio:
no effects observed
Changes in litter size and weights:
no effects observed
Changes in postnatal survival:
not examined
External malformations:
no effects observed
Skeletal malformations:
no effects observed
Visceral malformations:
no effects observed
Details on embryotoxic / teratogenic effects:
Embryotoxic / teratogenic effects:no effects

Details on embryotoxic / teratogenic effects:
There were no significant prenatal adverse effects.
A slight and dose related increase in the mean foetal body weight was observed, which was statistically significant in the high dose group. Observed malformations were of spontaneous nature with respect to number  and type

Effect levels (fetuses)

open allclose all
Key result
Dose descriptor:
NOAEL
Effect level:
135 mg/kg bw/day
Basis for effect level:
other: fetotoxicity
Key result
Dose descriptor:
NOAEL
Effect level:
135 mg/kg bw/day
Basis for effect level:
other: teratogenicity

Fetal abnormalities

Key result
Abnormalities:
no effects observed

Overall developmental toxicity

Key result
Developmental effects observed:
no

Any other information on results incl. tables

Summarised results on fertility and offspring

Control

15 mg/kg

45 mg/kg

135 mg/kg

Number of rats

used

25

25

25

25

pregnant

20

20

20

20

evaluated

20

20

20

17 (3 died pre-maturely)

Corporea lutea

total

277

272

272

223

per dam

13.9 ± 2.0

13.6 ± 2.1

13.6 ± 1.7

13.1 ± 1.4

Implantations

total

272

266

257

216

per dam

13.6 ± 1.9

13.3 ± 2.3

12.9 ± 2.3

12.7 ± 1.3

Foetuses

total

252

251

242

199

per dam

12.6 ± 2.3

12.6 ± 2.4

12.1 ± 2.4

11.7 ± 2.0

Number of placentae

252

251

242

199

Resorptions

total

20

15

15

17

per dam

1.0 ± 1.6

0.7 ± 1.1

0.8 ± 1.1

1.0 ± 1.5

Resorption rate (%)

7.4

5.6

5.8

7.9

Dead foetuses

0

0

0

0

Runts

total

1

0

1

0

per dam

0.1 ± 0.2

-

0.1 ± 0.2

-

Malformations

total

6

5

4

2

per dam

0.3 ± 1.3

0.3 ± 0.8

0.2 ± 0.6

0.1 ± 0.5

Malformation rate (%)

2.4

2.0

1.7

1.0

Foetuses with variations (Dawson)

99

108

97

79

Variation rate (%)

78.6

86.4

80.2

79.8

Foetuses with variations (macroscopic)

0

0

0

0

Foetuses with variations (Wilson)

19

17

14

21

Variation rate (%)

15.1

13.5

11.6

21.0

Body weights foetuses (g)

3.44 ± 0.24

3.52 ± 0.50

3.71 ± 0.61

3.75 ± 0.28

(t = 3.520)

Placenta weights (g)

0.57 ± 0.07

0.55 ± 0.06

0.56 ± 0.04

0.56 ± 0.06

Pre-implantation loss (%)

1.8

2.2

5.5

3.1

Post-implantation loss (%)

7.4

5.6

5.8

7.9

Applicant's summary and conclusion

Conclusions:
The test substance was not embyro- or foetotoxic and induced no malformations in rats at doses which produced maternal toxicity.
Executive summary:

Pregnant Sprague-Dawley rats (20 per group) were orally treated (tributylamine; purity of test item: 99.3%) by gavage on gestation days 6 -15 with doses of 15, 45 and 135 mg/kg/day. Three dams of the high dose group died prematurely on days 7 and 8. The other animals of this group showed transient reductions in food consumption and body weight gain. There were no embryo- or fetotoxic effects except a slight and dose-related increase in foetal body weight gain, which was significant at the highest dose. The treatment did not produce malformations (Hoechst/LPT, 1991).

The LOAEL for maternal toxicity was 135 mg/kg bw/day, the NOAEL 45 mg/kg bw/day. The NOAEL for developmental toxicity was 135 mg/kg bw/day, the highest dose tested. This study, performed according to OECD guideline 414, was judged to be reliable (RL1) and selected as key study.