Ammonium hydrogencarbonate

Developmental toxicity / teratogenicity

Administrative data

Endpoint:

developmental toxicity

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: Acceptable, well documented study which meets basic scientific principles.

Data source

Reference

Reference 1

Reference Type:

publication

Title:

Unnamed

Year:

1974

Reference 2

Reference Type:

publication

Title:

SIDS Initial Assessment Report For SIAM 15

Author:

OECD

Year:

2002

Bibliographic source:

OECD SIDS SODIUM BICARBONATE

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

Female Wistar rats were treated with sodium bicarbonate by oral intubation at doses of 3.4, 15.8, 73.3 and 340 mg/kg from day 6-15 of gestation. On day 20 all dams were subjected to Caesarean section and the number of implantation sites, resorption sites and live and dead fetuses were recorded. One-third of the fetuses of each litter underwent detailed visceral examinationswhile the remainings examined for skeletal defects.

GLP compliance:

no

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Sodium hydrogencarbonate

EC Number:

205-633-8

EC Name:

Sodium hydrogencarbonate

Cas Number:

144-55-8

IUPAC Name:

sodium hydrogen carbonate

Details on test material:

- Name of test material (as cited in study report): sodium bicarbonate

Test animals

Species:

rat

Strain:

Wistar

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Details on exposure:

VOLUME
At a dosage level of < 250 mg/kg the test material was dosed at 1 mI/kg. At a dosage of 340 mg/kg the test material was dosed at 2 ml/kg.

Analytical verification of doses or concentrations:

not specified

Details on mating procedure:

- Impregnation procedure: cohoused
- If cohoused:
- M/F ratio per cage: data not given
- Length of cohabitation: data not given
- Further matings after two unsuccessful attempts: data not given
- Verification of same strain and source of both sexes: data not given
- Proof of pregnancy: vaginal plug referred to as day 0 of pregnancy

Duration of treatment / exposure:

day 6 - 15 of gestation

Frequency of treatment:

once daily

Duration of test:

20 days

Doses / concentrations

Remarks:

Doses / Concentrations:
3.4, 15.8, 73.3, 340 mg/kg
Basis:
nominal conc.

No. of animals per sex per dose:

25

Control animals:

yes, sham-exposed

other: Aspirin: 250 mg/kg bw

Examinations

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily

DETAILED CLINICAL OBSERVATIONS: No data

BODY WEIGHT: Yes
- Time schedule for examinations: on days 0, 6,11, 15 and 20 of gestation

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): No data
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: No data
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: No data

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day # 17
- Organs examined: urogenital tract

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: No data
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes

Fetal examinations:

- External examinations: Yes: 1/3rd per litter
- Soft tissue examinations: Yes: 1/3rd per litter
- Skeletal examinations: Yes: 1/3rd per litter
- Head examinations: Yes: No data

Results and discussion

Results: maternal animals

Effect levels (maternal animals)

Dose descriptor:

NOAEL

Effect level:

>= 340 mg/kg bw/day (nominal)

Basis for effect level:

other: developmental toxicity

Results (fetuses)

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effects

Details on embryotoxic / teratogenic effects:
The number of abnormalities seen in either soft or skeletal tissues of the test groups did not differ from the number occurring spontaneously in the sham-treated controls

Fetal abnormalities

Abnormalities:

not specified

Overall developmental toxicity

Developmental effects observed:

not specified

Any other information on results incl. tables

Results:

	Sham	Aspirin (250 mg/kg bw)	Sodium bicarbonate (mg/kg bw)
			3.4	15.8	73.3	340
Pregnancies	20	24	20	21	21	22
Died or aborted	1	0	0	0	0	0
Live litters	19	19	20	21	21	22
Implant sites	226	277	239	268	238	254
Resorptions	5	93	3	0	0	1
Live fetuses	221	183	236	268	237	251
Dead fetuses	0	1	0	0	1	2
Fetus weight (g)	3.57	2.53	3.66	3.8	3.85	3.72