Ethanesulfonic acid, 2,2'-(hydroxyimino)bis-, sodium salt (1:2)

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:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Micronuclei induction in germ cells of the mouse was evaluated after after i.p. application. Due to the very alkaline character of the test and its application very close to the gonads the route of application chosen in this test is not suitable and results obtained are considered to be equivocal. For read-across justification refer to section 13.

Data source

Reference

Reference Type:

publication

Title:

Further evidence for the aneuploidogenic properties of chelating agents: induction of micronuclei in mouse male germ cells by EDTA

Author:

Russo A, Levis AG

Year:

1992

Bibliographic source:

Environ Mol Mutagen 19, 125-131

Materials and methods

Principles of method if other than guideline:

Micronuclei induction in germ cells of the mouse were evaluated after after i.p. application. In a second set of experiments chromosomal aberrations in mouse spermatogonia were determined.

GLP compliance:

no

Type of assay:

micronucleus assay

Test material

Test material information

Constituent 1

Reference substance name:

6381-92-6

Cas Number:

6381-92-6

IUPAC Name:

6381-92-6

Test material form:

solid - liquid: suspension

Details on test material:

- TS = Disodium EDTA dihydrate

Test animals

Species:

mouse

Strain:

Balb/c

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Italy
- Age at study initiation: 8 -12 weeks

Administration / exposure

Route of administration:

intraperitoneal

Details on exposure:

- Application volume: 10 ml/kg bw

Duration of treatment / exposure:

24 or 48 h (2 treatment sacrifice intervals)

Frequency of treatment:

single treatment

Doses / concentrations

Remarks:

Doses / Concentrations:
186 mg/kg bw
Basis:
other: actually applied

No. of animals per sex per dose:

6 control animals
3 for the 24 h interval
at least 4 for the 48 h interval

Control animals:

yes

Positive control(s):

5.5 mg/kg bw Adriamycin

Examinations

Tissues and cell types examined:

spermatids

Evaluation criteria:

The presence of MN was assessed on both Golgi and Cap phases of spermatid development, by scoring a minimum of 1000 Golgi phase spermatids per animal, and the Cap phase cells observed at the same time.

Results and discussion

Test results

Sex:

male

Genotoxicity:

positive

Remarks:

see table 1

Toxicity:

not specified

Negative controls validity:

not applicable

Positive controls validity:

valid

Any other information on results incl. tables

Table 1: Frequency of MN in early spermatids at two time intervals

	Golgi phase		Cap phase
	Total	+MN (‰ ± SE)	Total	+MN (‰ ± SE)
Controls	6,201	5 (0.8 ± 0.4)	5,836	3 (0.5 ± 0.3 )
ADM 24 hr	3,327	0	4,493	3 (0 .7 ± 0 .4)
ADM 48 hr	4,023	18 (4 .5 ± 1. 1)***	4,070	17 (4.2 ± 1.0)** *
EDTA 24 hr	2,993	9 (3.0 ± 1.0)*	3,436	2 (0 .6 ± 0 .4)
EDTA 48 hr	4,010	15 (3 .8 ± 1 .0)***	3,541	2 (0 .9 ± 0 .4 )

It was speculated by the authors whether EDTA induced MN either because of an S-independent clastogenic action of the compound under study, or for chromosome lagging.

Table 2: Chromosomal aberrations in mouse spermatogonia detected 24 h after treatment

 

	Metaphases scored		Aberrations per cell
	Total	Aberrant
Controls	200	1	0.005 +/- 0.0004
MMC	300	11	0.037 +/- 0.002 ***
ADM	201	15	0.085 +/- 0.007 ***
CH	247	2	0.008 +/- 0.0005
EDTA	400	2	0.005 +/- 0.0002

*** p<0.001

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information): positive
The results obtained indicate that EDTA-Na2H2 is able to induce micronuclei at meiosis. On the contrary, EDTA-Na2H2 did not induce chromosomal aberrations in mouse spermatogonia. Therefore, the most probable origin of micronuclei produced by EDTA is whole chromosome lagging. These results provide further evidence for the aneuploidogenic properties of these chelating agents.

Executive summary:

A micronucleus assay based on cytogenetic analysis of early spermatids (Tates et al. Mutation Research 121, 131 -138, 1983) was applied to determine if the chelating agent ethylenedinitrilotetraacetic acid (EDTA) may induce aneuploidy in mouse meiotic cells. Previous results indicated aneuploidogenic activity of EDTA in Drosophila female germ cells (induction of chromosome loss; Zordan et al., Environ Mol Mutagen 15:205-213, 1990). In the same study, a standard aneuploidy test based on chromosome counting in mouse secondary spermatocytes failed however to show aneuploidogenic properties of EDTA in mouse somatic and germ cells. In the present study the effects of two clastogens, adriamycin (ADM) and mitomycin C (MMC), and of the aneuploidogenic agent chloral hydrate (CH) were also evaluated. All compounds were tested at a single dose level and at two time intervals corresponding to the treatment of diakinesis / metaphase I /metaphase II spermatocytes. The clastogenic potential of the compounds under study was also evaluated, by chromosomal aberration analysis in mouse spermatogonia, in an independent set of experiments. The results obtained indicate that ADM, CH and EDTA are able to induce micronuclei at meiosis. On the contrary, only ADM and MMC induced chromosomal aberrations in mouse spermatogonia. Therefore, the most probable origin of micronuclei produced by CH and EDTA is whole

chromosome lagging. These results provide further evidence for the aneuploidogenic properties of these chelating agents.