Registration Dossier

Administrative data

Endpoint:
in vivo mammalian somatic cell study: cytogenicity / bone marrow chromosome aberration
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference
Reference Type:
publication
Title:
Genotoxic potency of three quinoline compounds evaluated in vivo in mouse marrow cells
Author:
McFee, A.F.
Year:
1989
Bibliographic source:
Environmental and Molecular Mutagenesis

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 475 (Mammalian Bone Marrow Chromosome Aberration Test)
GLP compliance:
not specified
Type of assay:
mammalian bone marrow chromosome aberration test

Test material

Specific details on test material used for the study:
8-hydroxyquinoline. Purity and batch not reported.

Test animals

Species:
mouse
Strain:
B6C3F1
Sex:
female
Details on test animals and environmental conditions:
Food and water were provided ad libitum. Mice were obtained from NTP contract supplier (Frederick Cancer Reseach Institute).

Administration / exposure

Route of administration:
intraperitoneal
Vehicle:
Corn oil
Duration of treatment / exposure:
17 h and 36 h for chromosomal aberrations. 23 h and 42 h for SCE analyses.
Frequency of treatment:
Single doses
Control animals:
yes, concurrent vehicle
Positive control(s):
7,12-dimethylbenz[a]anthracene (DMBA)

Examinations

Tissues and cell types examined:
Bone marrow cells
Details of tissue and slide preparation:
A single femur was removed, stripped of its adherent tissue, and the epiphyseal ends were snipped off. Cells were flushed into a centrifuge tube by approximately 6 ml of saline injected through a 25-gauge needle inserted into the marrow cavity. Tubes were centrifuged at 800g for 5 min, the saline was decanted, and cells were resuspended in 3 ml of hypotonic solution (0.01 M sodium citrate plus 0.05 M potassium chloride) and held at 37°C for 20 min. After centrifugation and decanting, cells were resuspended in 5 ml of 3: I methano1:acetic acid and washed through one additional change of 3:1 and one change of 2:l fixative before being resuspended in a small quantity (.25-.75 ml) of the 2:l fixative. Two drops of this cell suspension were dropped onto the flat surface of a clean microscope slide that had been freshly removed from cold,
distilled water, the fixative was ignited by touching the edge of the slide to an alcohol flame, and slides were placed on a warming plate (56°C) until completely dry. Slides were labeled with the animal number and stored for 24-96 h before being stained by the fluorescence-plus-Giemsa technique.
Evaluation criteria:
CAs were quantitated among 50 metaphases known to be at their first post-treatment division by their uniformly darkstained chromosomes; one-half of the cells were scored by each of two observers. For aberration scoring, gaps were defined as achromatic regions fully traversing the chromatid, but having a length equal to or less than the diameter of the chromatid; open regions of a greater extent or with obvious displacement of the distal segment of the chromatid were considered to be deletions. All anomalies were tabulated, and separate statistical analyses were performed on the data including and excluding the values for gaps. Sister chromatid exchanges were counted in 25 second-division metaphases from each animal sacrificed 23 h post-treatment; approximately one-half were scored by each observer. The rate of cell division was estimated for mice killed at 23 h by tabulating the proportion of first, second, and third or later metaphases among the first 100 encountered in a random scan of slides from each animal.
Statistics:
Statistical analyses of the data employed the one-tailed trend test of Margolin et al. [1986], based on individual animal responses and utilizing an alpha level of 0.05. Separate analyses were performed to determine if treatmentrelated increases occurred for SCEdcell and for average generation time; aberration data were separately analyzed for both the percent cells with at least one aberration and for the aberration ratekell, both values being independently analyzed with and without the inclusion of data for gaps.

Results and discussion

Test results
Key result
Sex:
female
Genotoxicity:
negative
Toxicity:
yes
Remarks:
at 70 and 100 mg/kg bw
Vehicle controls validity:
valid
Negative controls validity:
not examined
Positive controls validity:
valid
Additional information on results:
In first trial, 8-hydroxyquinoline was injected intraperitoneally at doses 25, 50 and 100 mg/kg bw. Due to lethality of high dose,doses were reduced to 17.5, 35 and 70 mg/kg bw in the second trial. High mortality was observed at the high dose level in the first and second trial, respectively.

Any other information on results incl. tables

Table 1. CAs and SCEs in marrow cells of mice injected with 8 -hydroxyquinoline. 17 h exposure.

Dose (mg/kg)  No. of mice % aberrant cells (±SE)
 0  8  0.50±0.33
 25  8  1.50±0.63
50  1.75±0.59
100  8  1.25±0.75
 DMBA  8 12.00±1.31
 TrendPvalue    .2410

Table 2. CAs and SCEs in marrow cells of mice injected with 8 -hydroxyquinoline. 23 h exposure.

Dose (mg/kg)  No. of mice % SCE/cell (±SE)
 0  4  5.49±0.40
 25  4  3.60±0.53
50  4.55±0.68
100  4  4.60±1.25
 DMBA  4  9.31±0.53
 TrendPvalue    .2578

Table 3. CAs and SCEs in marrow cells of mice injected with 8 -hydroxyquinoline. 36 h exposure.

Dose (mg/kg)  No. of mice % aberrant cells (±SE)
 0  8  4.75±1.31
 17.5  8  4.24±0.80
 35  4.50±1.76
 70  8  6.00±2.04
 DMBA  8  39.25±5.50
 TrendPvalue    .2438

Table 4. CAs and SCEs in marrow cells of mice injected with 8 -hydroxyquinoline. 42 h exposure.

Dose (mg/kg)  No. of mice % SCE cells (±SE)
 0  4  4.68±0.97
 17.5  4  4.61±0.26
 35 4  3.60±0.69
 70  4  3.99±0.04
 DMBA  4  9.23±0.97
 Trend P value    .1688

Applicant's summary and conclusion

Conclusions:
No induction of chromosomal aberrations in bone marrow cells was observed. Also, no increase in the rate of sister chromatid exchange was observed.
Executive summary:

8-hydroxyquinoline was assayed for the potential to induce chromosomal aberrations in bone marrow cells of B6C3F1 mice by single dose levels ranged from 17.5 to 100 mg/kg bw

(McFee, 1989). Sister chromatid exchanges in the marrow cells were also quantified. The study was non-GLP compliant and pre-guideline. Purity and batch specifications of the test

compound were unknown. In a first trial, 8-hydroxyquinoline was injected intraperitoneally at doses of 25, 50 and 100 mg/kg bw. Due to lethality of the high dose, doses were reduced to 17.5, 35 and 70 mg/kg bw in the second trial. High mortality, 42 and 40%, was observed at the high dose level in the first and second trial, respectively.

Under the conditions of this study, 8-hydroxyquinoline did not induce chromosomal aberrations in bone marrow cells of mice. Besides, no increase in the rate of sister chromatid

exchange was observed.