Registration Dossier

Toxicological information

Specific investigations: other studies

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Administrative data

Endpoint:
endocrine system modulation
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Scientifically valid GLP study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2005
Report date:
2005

Materials and methods

Test guideline
Qualifier:
no guideline available
Principles of method if other than guideline:
The ER competitive binding assay:
The assay conducted is based upon that described by Shelby et al (1996), but using the uteri of immature rats as a source of cytosolic ER. Immature animals are used, ensuring that most of the ER is free to bind the radioactive estradiol used in the assay.
GLP compliance:
yes
Type of method:
in vitro
Endpoint addressed:
other: hormone receptor binding

Test material

Constituent 1
Test material form:
solid: bulk
Details on test material:
Please refer to "Confidental details on test material".

Test animals

Details on test animals or test system and environmental conditions:
Please refer to "Further details on study design"

Administration / exposure

Details on exposure:
Please refer to "Further details on study design"
Details on study design:
The study consisted of harvesting the uteri from 40 immature Alderley Park rats. Freshly prepared cytosolic preparations of uterine tissue were then incubated with the test substance at a range of concentrations (0.5 nM to 0.5 mM) and a fixed concentration (5 nM) of the radiolabelled estrogen, 3H-estradiol in order to determine the ability of the test item to displace the 3H-estradiol.
Quantitation of displacement was used to determine the intrinsic activity of the test item to interact with the estrogen receptor (ER).
Two independent assays with duplicates in each assay were performed.

Results and discussion

Details on results:
FAT 65’080/B exhibited no displacement of 3H-estradiol at any of the concentrations tested. Displacement of 3H-estradiol was observed following incubation with increasing concentrations of non-radioactive estradiol (positive control) but not with DMSO (vehicle control).
Consistent results were obtained between duplicates within each assay and across both assays.

Applicant's summary and conclusion