Terphenyl, hydrogenated

Genetic toxicity: in vivo

Administrative data

Endpoint:

in vivo mammalian somatic cell study: cytogenicity / bone marrow chromosome aberration

Remarks:

Type of genotoxicity: chromosome aberration

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP-compliance study report, available as unpublished report, no restrictions, adequate for assessment

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1986

Report date:

1986

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 475 (Mammalian Bone Marrow Chromosome Aberration Test)

Principles of method if other than guideline:

Method: other: SRI International method

GLP compliance:

yes

Type of assay:

chromosome aberration assay

Test material

Test material information

Constituent 1

Reference substance name:

Terphenyl, hydrogenated

EC Number:

262-967-7

EC Name:

Terphenyl, hydrogenated

Cas Number:

61788-32-7

Molecular formula:

C18Hn (n >18-36)

IUPAC Name:

Terphenyl, hydrogenated

Test animals

Species:

rat

Strain:

Fischer 344

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Simonsen Laboratories Inc., 1180C Day Road, Gilroy, CA 95020
- Weight at study initiation: 175-275 g
- Assigned to test groups randomly: yes
- Housing: two or three per cage
- Diet (e.g. ad libitum): ad libitum (Certified Purina Lab Chow (#5002C))
- Water (e.g. ad libitum): ad libitum (Purified water)
- Acclimation period: minimum 5 days

Administration / exposure

Route of administration:

intraperitoneal

Vehicle:

- Vehicle(s)/solvent(s) used: corn oil
- Lot/batch no. (if required): 790670

Duration of treatment / exposure:

Single administration

Frequency of treatment:

Not applicable

Post exposure period:

Immediately after test article administration, near the end of the working day and (when appropriate) each day thereafter prior to sacrifice.

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

0 mg/kg bw/day (nominal)

Doses / concentrations 2

Dose / conc.:

250 mg/kg bw/day (nominal)

Doses / concentrations 3

Dose / conc.:

1 250 mg/kg bw/day (nominal)

Doses / concentrations 4

Dose / conc.:

2 500 mg/kg bw/day (nominal)

No. of animals per sex per dose:

number of animals: 18 animals per sex per dose
number of animals per sampling time: 6 animals per sex per dose

Control animals:

yes

yes, concurrent vehicle

Positive control(s):

triethylenemelamine (TEM, CAS n° 51-18-3)
- Route of administration: intraperitoneal injection
- Doses / concentrations: 0.2 mg/kg TEM dissolved in Hanks' balanced salt solution.
- Lot/batch no.: 9558

Examinations

Tissues and cell types examined:

Target cells: bone marrow cells

Details of tissue and slide preparation:

CRITERIA FOR DOSE SELECTION:
Based on the dose range-finding and the pilot studies

TREATMENT AND SAMPLING TIMES ( in addition to information in specific fields):
sampling times: 6, 12, 24 hours after dosing

DETAILS OF SLIDE PREPARATION:
Slides were prepared by dropping cell suspensions onto water-dipped slides, passing the slides through the flame of an alcohol lamp several times, and checking the cell density using a phase-contrast microscope. If cell density was too thick, more fixation was added to dilute the suspension. Based on the amount of cell suspension, six or fewer slides were prepared from each tube.
The slides were placed in 7% Giemsa (Gurr's R66 in m/15 Sorensen's buffer, pH 6.8) for 5 to 20 min. rinsed in distilled water, soaked in xylene, and mounted with Permount to make permanent slides for scoring under bright-field or phase-contrast optics (100x oil objective).

Evaluation criteria:

A test article was considered to have elicited a positive response in the in vivo bone marrow cytogenetic assay if either the mean aberrant cell frequency or the mean chromosomal aberration frequency per cell, or both, was significantly greater (P<0.05) in the test article-treated animals than in the negative control animals.

Statistics:

The following statistics were calculated for each animal: MI, the total number of chromosomal aberrations and the frequency of chromosomal aberrations per cell, the number and frequency of aberrations is each category, the number and frequency of cells with structurally aberrant chromosomes, the number and frequency of aneuploid (hyperploid) cells, the number and frequency of polyploid cells, and the number and frequency of several damaged cells.
These statistics have been analysed by the Bartlett's method, a one-way analysis of variance, the Dunnett's test and the Student's t-test.

Results and discussion

Test results

Sex:

male/female

Genotoxicity:

negative

Toxicity:

no effects

Vehicle controls validity:

valid

Positive controls validity:

valid

Additional information on results:

RESULTS OF RANGE-FINDING STUDY
- Dose range: 8, 40, 200, 1000 and 5000 mg/kg
- Clinical signs of toxicity in test animals:
At doses of 8, 40, 200 and 1000 mg/kg: There was no significant effect on body weight, no significant clinical signs of toxicity and no animals died.
At 5000 mg/kg: One male exhibited rough fur, humped backs, red exudate from the nose, slight diarrhea until it died. Another male exhibited rough fur and humped backs until the 14 days of the study.
At 5000 mg/kg: Females exhibited rough fur, humped backs, marked diarrhea and red exudate from the nose and the eyes. One female died.

RESULTS OF 24-HOUR PILOT STUDY
- Dose range: 0, 312, 625, 1250, 2500 and 5000 mg/kg
- Mitotic indices: no significant effect
- Clinical signs of toxicity in test animals:
At 2500 and 5000 mg/kg: Males and females exhibited negative changes in body weight, rough fur and humped backs.
No significant signs of toxicity were observed for animals treated with lower doses.

RESULTS OF 14-DAY PILOT STUDY
- Dose range: 312, 625, 1250, 2500 and 5000 mg/kg
- Clinical signs of toxicity in test animals:
At 5000 mg/kg: 4/5 males and 4/5 females died during the study. clinical signs of toxicity, rough fur, humped back, diarrhea, red exudates from the eyes and nose, slight hyperpnea
At 2500 mg/kg: weight gain reduction, clinical signs of toxicity, rough fur

RESULTS OF DEFINITIVE STUDY
- Clinical signs of toxicity in test animals:
At 250 mg/kg bw: no effects.
At 1250 mg/kg bw: a slight exudat from the left eye observed in one female.
At 2500 mg/kg bw: no effects; NOAEL.

Any other information on results incl. tables

Cytogenetic evaluation of bone marrow cells from female rats treated with Terphenyl, hydrogenated: 24-hour sacrifice

	Negative control	2500 mg/kg Terphenyl, hydrogenated	0.2 mg/kg
Number of animals	5	4	5
Mitotic Index (Mean % ±)	5.05 ± 0.44	6.36 ± 1.07	3.31 ± 0.34
Number of cells analyzed	300	240	300
Number of aberrant cells (Mean % ±)	0	2(0.83±0.83)	85(28.33±5.75)
Number of cells with structurally abnormal chromosomes (Mean % ±)	0	2(0.83±0.83)	82(27.33±5.52)
Number of cells (%) with:
Chromosome deletions	0	0	1 (0.40)
Chromosome exchanges	0	0	0
Chromatid deletions	0	2(0.83)	27 (10.89)
Chromatid exchanges	0	0	12 (4.84)
Aneuploidy	0	0	2 (0.81)
Polyploidy	0	0	1 (0.40)
Severe damage	0	0	52 (17.33)
Types of aberrations per cells:
Overall frequency of aberrations (Mean % ±)	0	3 (0.012)	329(1.097±0.267)
Chromosome deletions	0	0	1 (0.004)
Chromosome exchanges	0	0	0
Chromatid deletions	0	3 (0.012)	51 (0.206)
Chromatid exchanges	0	0	14 (0.056)
Number of cells (%) with:
Chromatid gaps	0	1 (0.42)	4 (1.61)
Chromosome gaps	0	0	0

 

Cytogenetic evaluation of bone marrow cells from male rats treated with Terphenyl, hydrogenated: 24-hour sacrifice

	Negative control	2500 mg/kg Terphenyl, hydrogenated	0.2 mg/kg
Number of animals	5	5	4
Mitotic Index (Mean % ±)	5.82 ± 0.31	7.22 ± 0.98	4.79 ± 0.65
Number of cells analyzed	300	300	300
Number of aberrant cells (Mean % ±)	1(0.33±0.33)	1(0.33±0.33)	73(24.33±3.71)
Number of cells with structurally abnormal chromosomes (Mean % ±)	0	0	72(24.0±3.6)
Number of cells (%) with:
Chromosome deletions	0	0	0
Chromosome exchanges	0	0	1 (0.38)
Chromatid deletions	0	0	32 (12.08)
Chromatid exchanges	0	0	14 (5.28)
Aneuploidy	1 (0.33)	0	1 (0.38)
Polyploidy	0	1 (0.33)	0
Severe damage	0	0	35 (11.67)
Types of aberrations per cells:
Overall frequency of aberrations (Mean % ±)	1(0.003±0.003)	1(0.003±0.003)	257(0.857±0.112)
Chromosome deletions	0	0	0
Chromosome exchanges	0	0	1 (0.004)
Chromatid deletions	0	0	65 (0.245)
Chromatid exchanges	0	0	15 (0.57)
Number of cells (%) with:
Chromatid gaps	2 (0.67)	0	7 (2.64)
Chromosome gaps	0	0	0

Applicant's summary and conclusion

Conclusions:

Interpretation of results: negative
Terphenyl, hydrogenated does not induce chromosomal damage in male or female Fischer-344 rats under the conditions used in this study.

Executive summary:

This study assessed the ability of Terphenyl, hydrogenated administered by intraperitoneal injection to induce chromosomal damage in bone marrow cells of Fischer-344 rats. In the definitive study, rats were given Terphenyl, hydrogenated at doses of 0, 250, 1250, and 2500 mg/kg body weight. Groups of animals were sacrificed 6, 12, and 24 hr after treatment. The positive control groups received triethylenemelamine (0.2 mg/kg body weight 1 by intraperitoneal injection and were sacrificed 24 hr after treatment. Cells from animals exposed to 0 and 2500 mg/kg and those from animals in the positive control groups were evaluated microscopically for mitotic indexand chromosomal abnormalities. On the basis of the results, it was concluded that Terphenyl, hydrogenated does not induce chromosomal damage in male or female Fischer-344 rats under the conditions used in this study.