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Toxicological information

Developmental toxicity / teratogenicity

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Administrative data

Endpoint:
developmental toxicity
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: pre-GLP
Cross-reference
Reason / purpose:
reference to other study

Data source

Reference
Reference Type:
publication
Title:
Unnamed
Year:
1987

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
Rats were dosed via diet during gestation day 6-15. Standard endpoints for teratogenicity were evaluated.
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Details on test material:
Ethylenediamine dihydrochloride was prepared from high purity ethylenediamine, 99,9%. The salt was analysed by chromatography and spectrophotometric methods, and found to be free of impurities.

Test animals

Species:
rat
Strain:
Fischer 344
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River Breeding Laboratories, Inc. (Kingston, NY).
- Age at study initiation: 100 days
- Housing: stainless-steel cages
- Diet : Purina Certified Rodent Chow 5002
- Water (e.g. ad libitum): Yes

Administration / exposure

Route of administration:
oral: feed
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Analysis indicated that the test diet preparations were accurate and homogeneous. The stability of the test diets was also confirmed. Substance was added to diet based on established diet consumption data and an established growth curve to produce the dosage goals.
Details on mating procedure:
At approximately 100 days of age, female rats were introduced into the male rats' cages. The rats were mated one male to one female to achieve a goal of approximately 20 pregnant females per treatment group, and 40 in the negative control group. Expelled vaginal plugs were used as evidence that mating had occurred
Duration of treatment / exposure:
Gestation day 6 - 15
Frequency of treatment:
daily
Duration of test:
cesarean section on gestation day 21
Doses / concentrationsopen allclose all
Remarks:
Doses / Concentrations:
50 mg/kg bw/day
Basis:

Remarks:
Doses / Concentrations:
250 mg/kg bw/day
Basis:

Remarks:
Doses / Concentrations:
1000 mg/kg bw/day
Basis:

No. of animals per sex per dose:
20 and 40 in control group.
Control animals:
yes, concurrent no treatment

Results and discussion

Results: maternal animals

Maternal developmental toxicity

Details on maternal toxic effects:
Maternal toxic effects:yes

Effect levels (maternal animals)

open allclose all
Dose descriptor:
NOAEL
Effect level:
23 mg/kg bw/day
Based on:
test mat.
Basis for effect level:
other: maternal toxicity
Dose descriptor:
LOAEL
Effect level:
114 mg/kg bw/day
Based on:
test mat.
Basis for effect level:
other: maternal toxicity

Results (fetuses)

Effect levels (fetuses)

open allclose all
Dose descriptor:
NOAEL
Effect level:
114 mg/kg bw/day
Based on:
test mat.
Basis for effect level:
other: fetotoxicity
Dose descriptor:
LOAEL
Effect level:
454 mg/kg bw/day
Based on:
test mat.
Basis for effect level:
other: fetotoxicity

Fetal abnormalities

Abnormalities:
not specified

Overall developmental toxicity

Developmental effects observed:
not specified

Any other information on results incl. tables

Significant reduction in maternal body weight gain in the intermediate dose group during gestation day 6 - 15 and in the high dose group during gestation day 6 - 21; significant decreased diet consumption in the intermediate and high dose group during gestation day 6 - 15; significant increased number of resorptions/litter and significant decreased mean fetal body weight and reduced fetal crown-rump length in the high dose group; significant higher incidence of a shortened mandible, edematous eye bulge, shortened or missing innominate artery, unossified sternebrae in fetuses of the high dose group.

    Number of pups affected
    Dosage level (mg/kg/day)
           Control 50 250 1000
No. of litters   40 23 21 24
No. of pups   379 232 201 242
           
Pup body weight, males (g)        4.5+0.3 4.5+0.2  4.5+0.2  4.1+0.3
 Pup body weight, females (g)   4.2+0.2  4.2+0.2 4.2+0.3  3.8+0.3
           
Fetal crown rump length, males (mm)    40+2    40+2     40+2      39+2
 Fetal crown rump length, females (mm)   38+1    39+2     39+2      37+2
           
Slightly edematous eye bulge          
  F 0 0 0 4
  L 0 0 0 4
Shortened mandible           
  F 0 0 0 18
  L 0 0 0 4
Missing innominate artery          
  F 0 0 1 9
  L 0 0 1 6
Shortened innominate artery          
  F 4 2 0 27
  L 4 1 0 14

F = fetuses L = litters

The first artery to branch off of the aorta is the brachiocephalic which becomes the innominate after the left carotid branches off.  The innominate then branches into the right subclavian and right carotid artery.  When the authors stated it was missing, they really mean that the right and left carotid branch off of the brachiocephalic artery at the same time.  Thus there is no innominate.  However, this would not affect blood supply to areas served by these arteries.                                                                                                                           

Applicant's summary and conclusion

Conclusions:
The fetal alterations were either of questionable teratologic significance or indicative of growth retardation, possibly as a result of reduced food consumption.
The most important finding was an increase in the incidence of missing and shortened innominate artery. Further testing was performed to determine if this was an effect of malnutrition from reduced food consumption.
Executive summary:

Fischer 344 rats were fed EDA*2HCl on gestation day 6-15. Groups of 20 rats were fed doses 50, 250, or 1000 mg/kg. Two control groups were used. Standard endpoints for teratogenicity were evaluated.

Reduction in maternal body weight gain was noted in the high and intermediate dose group. Reduced diet consumption was also noted in those groups. In the high dose group there was an increased number of resorptions/litter, decreased mean fetal weight and length, higher incidence of shortened mandible, edematous eye bulge, shortened or missing sternebrae, delayed ossification and missing, or shortened innominate arteries.