Registration Dossier

Administrative data

Endpoint:
additional toxicological information
Type of information:
experimental study
Adequacy of study:
supporting study
Study period:
8 days
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Reliable without restriction; study followed acceptable scientific principles.

Data source

Reference
Reference Type:
publication
Title:
Unnamed
Year:
2005

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
Five pregnant Sprague-Dawley rats were exposed from gestation day 12 through gestation day 19 to di (2-ethylhexyl) terephthalate at 500 mg/kg bw/day. On gestation day 19, all females were euthanized by carbon dioxide inhalation and a laprohysterectomy was performed. Fetuses were weighed, anogential distance obtained, and fetuses were decapitated. After decapitation, fetuses were sexed and the right and left testes were removed and snap-frozen in liquid nitrogen until gene expression analysis was carried out. Global gene expression in the fetal testis was determined for gene pathways involved in: cholesterol transport and steroidogenesis, intracellular lipid and cholesterol homeostasis, insulin signaling, transcriptional regulation, oxidative stress, alpha inhibin (essential for normal Sertoli cell development), and genes involved in communication between Sertoli cells and gonocytes.
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Details on test material:
-Name as cited in publication: diethylhexyl phthalate (DEHP)

Results and discussion

Any other information on results incl. tables

-Anogenital Distance:

Anogenital distance was not significantly different in male fetuses exposed to di (2-ethylhexyl) terephthalate (1.6344 ± 0.03) relative to control (1.61 ± 0.02).

  

-Microarray analysis and gene ontology:

A heat map was generated to compare the expression level of 391 genes between the treatment group relative to a universal mean. The list of 391 significant genes contained 225 unknown and uncharacterized transcribed sequences, which were not considered in the classification. The remaining 167 genes were grouped into the following categories: related to lipid, sterol, and cholesterol homeostatis (31 genes); related to lipid, sterol, and cholesterol transport (10 genes); steroidogenesis (12 genes); transcription factors (9 genes); signal transduction (22 genes); oxidative stress (11 genes); and cytoskeleton-related (13 genes). 

  

-Quantitation of gene expression by real-time RT-PCR:

None of the genes from animals exposed to di (2-ethylhexyl) terephthalate were changed in a statistically significant manner compared to controls.

Applicant's summary and conclusion

Conclusions:
Five pregnant Sprague-Dawley rats were exposed from gestation day 12 through gestation day 19 to di (2-ethylhexyl) terephthalate at 500 mg/kg bw/day. On gestation day 19, all females were euthanized by carbon dioxide inhalation, fetuses were weighed, and anogential distance was obtained. Fetuses were sacrificed, sexed, and the right and left testes were removed. Genes associated with pathways involving lipid, sterol, and cholesterol transport, steroidogenesis, intracellular lipid and cholesterol homeostasis, oxidative stress, insulin signaling, and transcriptional regulation, were evaluated in the present study using Real-time Quantitative Reverse Transcription-Polymerase Chain Reactions. A total of 18 genes were investigated. No statistically significant alterations were noted in any of these genes in animals exposed to di (2-ethylhexyl) terephthalate.

Based on an absence of adverse effects on major gene pathways that allow for normal male reproductive tract development, di (2-ethylhexyl) terephthalate is not expected to be classified for “Germ Cell Mutagenicity” according to GHS.
Executive summary:

In the present study, five pregnant Sprague-Dawley outbred CD rats were exposed to di (2-ethylhexyl) terephthalate from gestation day 12 through 19 at 500 mg/kg bw/day. Ten pregnant Sprague-Dawley rats were also administered the vehicle (corn oil) and served as the controls. After administering the last dose on gestation day 19, all dams were euthanized by carbon dioxide asphyxiation and a laprohysterectomy was performed. Fetuses were removed, weighed, anogenital distance obtained, sexed, and the testes were removed from male fetuses. Anogenital distance was not significantly altered in male fetuses exposed to the test substance and none of the genes representing major gene pathways that allow for normal male reproductive tract development were altered by exposure to di (2-ethylhexyl) terephthalate.