Slags, ferronickel-manufg.

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: see 'Remark'

Remarks:

Study was performed before EU/OECD protocol establishment and no guideline is mentioned. Data on reproductive and developmental toxicity for slags, ferronickel-manufg. is not available for the whole substance. Until a relevant study is performed on slags, ferronickel-manufg., it was attempted to identify possible adverse effects based on data for its recognised constituents, even though the results cannot be applied directly, due to the way the constituents are bound in the matrix of the substance and are not as bioavailable as the free substances that are examined. So, the results must be taken into consideration with care.

Data source

Reference

Reference Type:

publication

Title:

Potential toxicity of iron overload in successive generations of rats

Author:

R.O. Fisch,M.D., A.S. Deinard, M.D., L.J. Disch, B.A., and W. Krivit

Year:

1975

Bibliographic source:

The American Journal of Clinical Nutrition 28: 136-139

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

No guideline mentioned in the study

GLP compliance:

no

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Iron

EC Number:

231-096-4

EC Name:

Iron

Cas Number:

7439-89-6

Molecular formula:

Fe

IUPAC Name:

iron

Details on test material:

parenteral iron (Imferon 20 mg/kg)

Test animals

Species:

rat

Strain:

Sprague-Dawley

Details on test animals or test system and environmental conditions:

Six week old Sprague-Dawley rats, fed on Purina Chow.

Administration / exposure

Route of administration:

intramuscular

Vehicle:

not specified

Details on exposure:

The experimental 16 females were given parenteral iron (Imferon: 20 mg/kg) by intramuscular injection according to the following schedule:
7 & 8-week old: 1 injection of 20mg/kg per week
9 &10-week old: 2 injections of 20mg/kg per week
11 & 12-week old: 3 injections of 20mg/kg per week

The total amount of iron given was approximately 62-72 mg/animal during the 6-week period of injections. Following the last injection at 1 2 weeks of age, the treated females received no iron for 1 week, following which they and the control females were allowed to mate with the males. During pregnancy, no female received iron injections.

Analytical verification of doses or concentrations:

not specified

Details on analytical verification of doses or concentrations:

not applicable

Details on mating procedure:

After the last injection on the females were 12 weeks old, followed 1 week without iron supplementation and then they were allowed to mate with the males. When the offspring was 6 weeks old random separation and repetition of the experiment until fourth generation was performed. Interbreeding was carefully avoided.

Duration of treatment / exposure:

7 & 8-week old: 1 injection of 20mg/kg per week
9 &10-week old: 2 injections of 20mg/kg per week
11 & 12-week old: 3 injections of 20mg/kg per week

Frequency of treatment:

7 & 8-week old: 1 injection of 20mg/kg per week
9 &10-week old: 2 injections of 20mg/kg per week
11 & 12-week old: 3 injections of 20mg/kg per week

Duration of test:

6-week period of injections, until the animals were 12 weeks of age.

Doses / concentrations

Remarks:

Doses / Concentrations:
between 62 and 72 mg/animal during the 6-week injection period
Basis:
actual ingested

No. of animals per sex per dose:

16 animals in the first generation (G-1)

Control animals:

yes, concurrent no treatment

Details on study design:

After the last group of females (G-4) delivered their offspring (G-5), every other female and all of her offspring were sacrificed within 12 hours of birth (Fig. 1). In all, eight treated females and their 72 offspring, as well as four control females and their 49 offspring, were sacrificed. This occurred, in general, immediately after birth and always by 12 hours of age. The sacrificed animals were assayed for total body iron content. Seven experimental females and their 62 offspring, as well as two control females and their 1 3 offspring, were allowed to live to 6 weeks of age (one female died during labor), at which time both females and offspring were weighed.

Examinations

Maternal examinations:

Iron assay performed in triplicate on each adult rat that was sacrificed.
Growth, as measured by weight, was also examined.

Ovaries and uterine content:

no data

Fetal examinations:

Iron assay. The cadaver of each newborn rat was sectioned and dried at 110 C overnight. The dried tissue was weighed and digested in 3 ml of distilled water and 10 ml of concentrated nitric acid (redistilled by C. F. Smith Chemical Co., Columbus, Ohio). The resulting solution was gently boiled until clear and allowed to cool. The solid lipid layer that formed was removed by filtration through iron-free glass wool. Additional concentrated
nitric acid was used to rinse the lipid solids and bring the total sample volume to 25 ml. A 2-ml aliquot of the “whole-rat” solution and 10 ml of concentrated nitric acid were further digested by boiling to one-third original volume. At this point, another 10 ml of concentrated nitric acid were added and the solution was redigested. The remaining liquid was made up to a volume of 10 ml with concentrated nitric acid and its iron concentration was determined on an atomic absorption spectrophotometer using a Fischer iron standard (1-7 ppm) and concentrated nitric acid as a blank.

Statistics:

The test of the reproducibility of iron determination was done on three different days on the offspring animals. The mean coefficient of variance (CV = 100SD/’X) was 6.6%. When this assay method was applied to situations where known concentrations of iron were present, the average percent recovery of iron was 85%.

Indices:

litter size (viability of offspring)
litter weight
litter iron body burden
litter rate of growth

Historical control data:

no data

Results and discussion

Results: maternal animals

Maternal developmental toxicity

Details on maternal toxic effects:

Maternal toxic effects:no effects

Details on maternal toxic effects:
No toxic effects observed.

Effect levels (maternal animals)

Dose descriptor:

NOAEC

Effect level:

> 62 - < 72 other: mg/animal

Based on:

element

Remarks:

iron

Basis for effect level:

other: other:

Results (fetuses)

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effects

Details on embryotoxic / teratogenic effects:
No such effects observed

Fetal abnormalities

Abnormalities:

not specified

Overall developmental toxicity

Developmental effects observed:

not specified

Any other information on results incl. tables

No differences in litter size (viability of offspring). No differences in litter weight. No differences in litter iron body burden. No differences in litter rate of growth

Applicant's summary and conclusion

Conclusions:

The toxicity of iron overload on successive generations was tested in female rats from generation 1 to generation 5 included. Test group received a total amount of 62-72 mg/animal during a 6 week period of dosing parenterally. This route was chosen because iron given orally is absorbed in limited quantities. When the offspring was 6 weeks old random separation and repetition of the experiment until fourth generation was performed. Mothers and offspring were examined for iron body burden, litter size and litter postnatal development. No differences in litter size (viability of offspring), litter weight, litter iron body burden and litter rate of growth was noted. It can be concluded that iron overload did not affect embryo rat development in subsequent generations.

Executive summary:

The toxicity of iron overload on successive generations was tested in female rats from generation 1 to generation 5 included. Test group received a total amount of 62-72 mg/animal during a 6 week period of dosing parenterally. This route was chosen because iron given orally is absorbed in limited quantities. When the offspring was 6 weeks old random separation and repetition of the experiment until fourth generation was performed. Mothers and offspring were examined for iron body burden, litter size and litter postnatal development. No differences in litter size (viability of offspring), litter weight, litter iron body burden and litter rate of growth was noted. It can be concluded that iron overload did not affect embryo rat development in subsequent generations