Slags, ferronickel-manufg.

Toxicity to reproduction

Administrative data

Endpoint:

multi-generation reproductive toxicity

Remarks:

based on test type (migrated information)

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

Remarks:

Study was performed before the establishment of GLP

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:

No further details

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

female

Details on test animals or test system and environmental conditions:

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

Administration / exposure

Route of administration:

intramuscular

Type of inhalation exposure (if applicable):

other: not applicable

Vehicle:

unchanged (no vehicle)

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.

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.

Analytical verification of doses or concentrations:

no

Details on analytical verification of doses or concentrations:

not applicable

Duration of treatment / exposure:

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

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

Doses / concentrations

Remarks:

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

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.

Positive control:

No

Examinations

Parental animals: Observations and examinations:

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

Oestrous cyclicity (parental animals):

no data

Sperm parameters (parental animals):

no data

Litter observations:

No differences in litter size between test group and control group.

Postmortem examinations (parental animals):

Iron assay. See "postmortem examinations (Offspring) for details. In this case, the initial digestion was done in 300 ml of distilled water and I liter of concentrated nitric acid. The “whole-rat” solution of this digest was filtered and diluted to 2 liters. Two-milliliter aliquots were then treated as described above. The iron assay for each of the adult rats was done in triplicate.

Postmortem examinations (offspring):

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%.

Reproductive indices:

no information

Offspring viability indices:

No differences in litter size was observed.

Results and discussion

Results: P0 (first parental generation)

General toxicity (P0)

Clinical signs:

no effects observed

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

increased body weight in iron-treated females

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

increased body weight in iron-treated females

Organ weight findings including organ / body weight ratios:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Other effects:

effects observed, treatment-related

Description (incidence and severity):

Test substance intake: total body iron of adult females was significantly higher in test group

Reproductive function / performance (P0)

Reproductive function: oestrous cycle:

not examined

Reproductive function: sperm measures:

not examined

Reproductive performance:

no effects observed

Effect levels (P0)

Dose descriptor:

LOAEC

Effect level:

> 62 - < 72 other: mg/animal

Based on:

test mat.

Sex:

female

Basis for effect level:

other: The only observable effects were on the weight of the mothers, which was greater for the test group. No differences were observed in the litter size.

Remarks on result:

other: Generation: 1st generation (parent) (migrated information)

Results: F1 generation

General toxicity (F1)

Clinical signs:

no effects observed

Mortality / viability:

no mortality observed

Body weight and weight changes:

no effects observed

Sexual maturation:

no effects observed

Description (incidence and severity):

offspring reproduced normally

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

no effects observed

Description (incidence and severity):

nothing observable

Histopathological findings:

not examined

Overall reproductive toxicity

Reproductive effects observed:

not specified

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. Mother weight was higher in the iron-treated females but no differences in litter size (viability of offspring) were noted. It can be concluded that iron overload did not affect fertility of female rats 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 wereexamined for iron body burden, litter size and litter postnatal development. Mother weight was higher in the iron-treated females but no differences in litter size (viability of offspring) were noted. It can be concluded that iron overload did not affect fertility of female rats in subsequent generations