2-(2-aminoethoxy)ethanol

Genetic toxicity: in vivo

Administrative data

Endpoint:

in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus

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 guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2001

Report Date:

2001

Materials and methods

Test guideline

Qualifier:

according to

Guideline:

EPA OPP 84-2

GLP compliance:

yes

Type of assay:

micronucleus assay

Test material

Reference

Name:

Unnamed

Type:

Constituent

Test animals

Species:

mouse

Strain:

CD-1

Sex:

male

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Charles River laboratories, Kingston,NY
- Diet (e.g. ad libitum): ad libitum (PMI Feeds,Inc. Certified Rodent Diet #5002)
- Water (e.g. ad libitum): ad libitum
- Acclimation period: at least 6 days

ENVIRONMENTAL CONDITIONS
- Temperature : 64-79 °F ( 18-26 °C)
- Humidity (%): 30 - 70
- Air changes (per hr): at least 10 per hour
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

intraperitoneal

Duration of treatment / exposure:

The animals were treated once and samples of bone marrow were taken 24 h and 48 h after the treatment.

Frequency of treatment:

The animals were treated once.

Doses / concentrations

Remarks:

Doses / Concentrations:
62.5, 125, 250 mg/kg
Basis:

No. of animals per sex per dose:

6 male animals per dose

Control animals:

yes, concurrent vehicle

Positive control(s):

cyclophosphamide

Examinations

Tissues and cell types examined:

At least 2000 PCEs per animal were analyzed for the frequency of mironuclei. Cytotoxicity was assessed by scoring the numer of PCEs and normochromic erythrocytes (NCEs) in at least 500 erythrocytes for each animals.

Details of tissue and slide preparation:

CRITERIA FOR DOSE SELECTION: Pretest were performed

DETAILS OF SLIDE PREPARATION:
Preparation of Slides. Following centrifugation to pellet the tissue, the supematant was removed by aspiration and portions of the pellet were spread on slides and air dried. The slides were fixed in methanol, stained in May-Grünwald Solution followed by Giemsa, and protected by permanently mounted coverslips. For control of bias, all slides were coded prior to analysis.
Slides prepared from the bone marrow collected from five animals per group, if available, at the designated harvest timepoints were scored for micronuclei and the PCE to NCE cell ratio. The micronucleus frequency (expressed as percent micronucleated cells) was determined by analyzing the number of micronucleated PCEs from at least 2000 PCEs per animal. The PCE:NCE ratio was determined by scoring the number of PCEs and NCEs observed scoring at least the first 500 erythrocytes per animal. The historical background frequency of micronucleated cells were expressed as percent micronucleated cells based on the number of PCEs analyzed. The historical background frequency of micronuclei in the Cr1:CD-lB(ICR) BR strain at this laboratory is about 0.0 to 0.4%, which is within the range reported in the published data (Salamone and Mavoumin, 1994). The critena for the identification of micronuclei were those of Schmid (1976). Micronuclei were darkly stained and generally round, although almond- and ring-shaped micronuclei occasionally occurred. Micronuclei were sharp bordered and generally between one-twentieth and one-fifth the size of the PCEs. The unit of scoring was the micronucleated cell, not the micronucleus; thus, the occasional cell with more than one micronucleus was counted as one micronucleated PCE, not two (or more) micronuclei. The staining procedure pennitted the differentiation by color of PCEs and NCEs (bluish-gray and red, respectively).

Evaluation criteria:

Assay data analysis was pedormed using an analysis of variance (Winer, 1971) on untransformed proportions of cells with micronuclei per animal and on untransformed PCE:NCE ratios when the variances were homogeneous. Ranked proportions were used for heterogeneous variances. If the analysis of variance was statistically significant (p <0.05), a Dunnett's t-test (Dunnett, 1955; 1964) was used to determine which dose groups, if any, were statistically significantly different from the vehicle control. Analyses were performed separately for each sampling time. The cnteria for a positive response was the detection of a statistically significant increase in micronucleated PCEs for at least one dose level, and a statistically significant dose-related response. A test article that did not induce both of these responses was considered negative. Statistical significance was not the only determinant of a positive response; the Study Director also considered the biological relevante of the results in the final evaluation.

Results and discussion

Test results

Sex:

male

Genotoxicity:

negative

Toxicity:

yes

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Any other information on results incl. tables

Micronucleus Data Summary Table

 

Treatment	Dose	Harvest Time	% Micronucleated PCEs mean of 2000^a Per animals ± S.E. males	Ratio PCE:NCE Mean ± S.E. Males
Controls
Vehicle	0.5 % CMC	24 hr	0.09 ± 0.04	0.67 ± 0.09
		48 hr	0.12 ± 0.03	0.51 ± 0.02
Positive	CP 80 mg/kg	24 hr	1.17 ± 0.12*	0.55 ± 0.06
Test article	62.5 mg/kg	24 hr	0.06 ± 0.02	0.61 ± 0.05
	125 mg/kg	24 hr	0.06 ± 0.02	0.48 ± 0.05
	250 mg/kg	24 hr	0.07 ± 0.03	0.41 ± 0.04**
		48 hr	0.21 ± 0.08	0.41 ± 0.05

 

 

*Significantly greater than the corresponding vehicle control, ps0.01.

** Significantly less than the corresponding vehicle control, ps0.05.

^aOne animal from the 24-hour vehicle control group and two animais from the 62.5 mg/kg dose goup were scored out of >2000 PCE/animal. See individual animal data, Table 2.

CMC = Carboxymethy1 cellulose

CP = Cyclophosphamide

PCE = Polychromatic erythrocyte

NCE = Normochromatic erythrocyt

Applicant's summary and conclusion

Conclusions:

The test article, Diglycolamine (DGA), was evaluated as negative in the mouse bone marrow micronucleus assay under the conditions of this assay.