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Toxicity to reproduction: other studies

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Administrative data

Endpoint:
toxicity to reproduction: other studies
Type of information:
migrated information: read-across based on grouping of substances (category approach)
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Research paper study well documented meeting generally accepted scientific principles.

Data source

Reference
Reference Type:
publication
Title:
Genome-linked toxic responses to dietary iron overload.
Author:
Whittaker P, Dunkel VC, Bucci TJ, Kusewitt DF, Thurman JD, Warbritton A, Wolff GL.
Year:
1997
Bibliographic source:
DOI 10.1177/019262339702500604 PMID 9437799 Toxicol Pathol 25(6):556-64. http://tpx.sagepub.com/content/25/6/556.full.pdf

Materials and methods

Principles of method if other than guideline:
This study was undertaken to evaluate genome-related differences to iron overload between and within rodent species.
GLP compliance:
not specified
Type of method:
in vivo

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
carbonyl iron

Test animals

Species:
other: Fischer 344 rats, B6C3F1 mice and yellow and black C5YS F1 mice.
Strain:
other:
Sex:
male

Administration / exposure

Route of administration:
oral: feed
Duration of treatment / exposure:
12 weeks
Frequency of treatment:
ad lib
Doses / concentrations
Remarks:
Doses / Concentrations:
1500; 3500; 5000; 10000 µg iron/g diet
Basis:

Control animals:
other: Yes, 35 µg carbonyl iron/g diet
Details on study design:
Groups of 12 male Fischer 344 rats were housed in pairs and groups of 12 male B6C3F1 (strain B) mice and yellow and black C5YS F1 (strain C) mice were housed 4/cage. All groups received food and water ad lib for a 12 week period The test materials were incorporated into the diet as follows: Controls: diet +35 ug iron/g diet, treatment groups: diet + 1,500 ug iron/g diet, diet + 3,500 ug iron/g diet, diet + 5,000 ug iron /g diet and diet + 10,000 ug iron/g diet. Final body weight and food consumption were recorded.
At the end of the test period the animals were fasted for 15 hours and a complete necroscopy was performed at sacrifice. Organ weights were determined. Tissues were fixed in 10% neutral formalin, and sections divided into two sets. One set was stained with haematoxylin and eosin (H&E), and another set was reacted with Perl's Prussian blue for Fe. Non-haem iron was determined by the bathophenanthroline reaction. Cell proliferation indices in the liver were determined by immunohistochemical localisation of proliferation cell nuclear antigen (PGNE). Effects of Fe on the pancreas were determined by immunohistochemical identification and determination of the numbers of alpha, beta and delta cells in the islets of Langerhans in the control and the 10,000 ug/g groups of mice and the 5,000 ug/g rat group.
Statistical significance was determined by one-way ANOVA or regression analysis using the ABstat general linear model program. Duncan multiple comparison method was used to differentiate among means for variables significantly affected by treatment. Significance was at p<0.05.Correlation coefficients were determined using Pearson's product moment correlation matrix. Mean organ:brain weight ratios were compared using Student's t-tests. Immunohistochemical assays and pancreas morphology data were compared by ANOVA with Holm's correction.

Results and discussion

Effect levels

Dose descriptor:
NOAEC
Effect level:
5 mg/kg diet
Based on:
test mat.
Remarks:
carbonyl iron

Observed effects

In rats, there were 9 mortalities in the highest dose group, and a dose-dependent reduction in body weight was observed. In mice, body weight was unaffected in the strain B and the black strain C mice, but in the yellow strain C there was a marked reduction in body weight at the highest dose. Food intake was decreased in strain B and yellow strain C mice, but unaffected in black strain C mice.
All animals showed a dose-related increase in liver non-haem Fe, and the Fe was stored in hepatocytes, principally in the periportal region. Significant hypertropy of the hepatocytes was observed in B6C3F1 mice and F344 rats at the highest dose.
The PCNA assays showed stimulation of hepatocyte proliferation in the F344 rats and the strain C mice at the highest dose. (In comparison with control; not determined at lower doses).
In the rat there was pancreatic atrophy with loss of endocrine and exocrine tissue at the 3,500 ug/g dose.
Beta cells in the pancreas were reduced in strain B and yellow strain C mice, but not in black strain C mice. Islet numbers and total and mean islet areas were reduced in yellow strain C mice at the highest dose. (In comparison with control; not determined at lower doses).
Rats showed exacerbated dose-dependent nephropathy and changes in glomerular and tubular epithelium associated with Fe accumulation at the highest dose. Degeneration of the germinal epithelium of the testis, formation of multinucleated giant cells and lack of mature sperm were observed in rats at the highest dose.

Applicant's summary and conclusion

Conclusions:
The results suggest absorbable iron complexes can adversely affect the male reproductive system under conditions of iron overload. Mortality was observed in 75% of rats at the highest dose, at which effects in the testes were observed.