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Toxicity to reproduction: other studies

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Administrative data

Endpoint:
toxicity to reproduction: other studies
Type of information:
experimental study
Adequacy of study:
weight of evidence
Reliability:
4 (not assignable)
Rationale for reliability incl. deficiencies:
other: Only basic data given

Data source

Reference
Reference Type:
publication
Title:
Estrogenic Activities of 517 Chemlicals byYeast Two-Hybrid Assay
Author:
Tsutomu Nishihara,
Year:
2000
Bibliographic source:
Journal of Health Science 46(4) 282-298

Materials and methods

Principles of method if other than guideline:
In this study, the yeast two-hybrid assay system with the estrogen receptor, ERa, and the coactivator, TIF2, was used to estimate estrogenic activity.
GLP compliance:
no
Type of method:
in vitro

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): 4-Hydroxyacetophenone

Administration / exposure

Duration of treatment / exposure:
4h
Frequency of treatment:
once
Details on study design:
Yeast Two-Hybrid Assay -- In this study, the yeast two-hybrid assay system with the estrogen receptor, ERa, and the coactivator, TIF2, was used. Briefly, two expression plasmids, pGBT9-ERLBD and pGAAD424-TIF-2, were introduced into yeast cells (Saccharomyces cerevisiae Y190), which carry a ß-galactosidase reporter gene and require tryptophan and leucine for growth. The cells were preincubated overnight at 30°C in SD medium free from tryptophan and leucine. The culture (250 ul) in a small test tube was then mixed with a DMSO solution (2.5 ul) of test chemical and incubated for 4 h at 30°C. After washing by centrifugation, the cells were digested enzymatically by incubation with 1 mg/ml Zymolyase 20T (200 ul) at 30°C for 15 min. The lysate was mixed with 4 mg/ml ONPG (40 ul) and reacted until development of a yellow color (usually 30 min) before the reaction was stopped by the addition of 1 M Na2C03 (100 ul). An aliquot (150 ul) was taken into each of 96 wells of a microplate. Absorbances at 420 and 550 nm were read on a microplate reader to estimate estrogenic activity.
Statistics:
The results were evaluated by relative activity, expressedas REC10 (10% relative effective concentration), that is the concentration of the test chemical showing 10% of the agonist activity of 10^-7 M E2, which is the optimum concentration for E2. When the activity of the test substance was higher than REC10 within the concentration tested, it was judged as positive. When it was judged to be negative, the highest dose tested was indicated.

Results and discussion

Any other information on results incl. tables

The REC10 was 2x10 -4 and test substance was stated by the authors to be tested as positive.

Applicant's summary and conclusion