Uronium hydrogen sulphate

Genetic toxicity: in vivo

Administrative data

Endpoint:

in vivo mammalian germ cell study: cytogenicity / chromosome aberration

Remarks:

Type of genotoxicity: chromosome aberration

Type of information:

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

Adequacy of study:

supporting study

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

other: Published study; non-standard method. The study is poorly reported and its value/relevance limited by the extreme dose level used, which is well in excess of the currently accepted limit dose.

Data source

Reference

Reference Type:

publication

Title:

EFFECTS OF UREA ON MITOTIC CHROMOSOMES OF MICE AND ONION

Author:

Chaurasia, O.P. & Sinha, S.P.

Year:

1987

Bibliographic source:

Cytologia 52(4): 877-882

Materials and methods

Principles of method if other than guideline:

Bone marrow cytogenetic assay in mice

GLP compliance:

not specified

Remarks:

: published study

Type of assay:

chromosome aberration assay

Test material

Test material information

Constituent 1

Reference substance name:

Urea

EC Number:

200-315-5

EC Name:

Urea

Cas Number:

57-13-6

IUPAC Name:

urea

Details on test material:

No information available; purity unknown

Test animals

Species:

mouse

Strain:

Swiss

Sex:

not specified

Details on test animals or test system and environmental conditions:

Swiss albino mice

Administration / exposure

Route of administration:

oral: feed

Vehicle:

Diet

Details on exposure:

Mice were fed 500 mg/animal per day in food for 5 days

Duration of treatment / exposure:

5 days

Frequency of treatment:

Daily

Post exposure period:

Seven days

Doses / concentrations

Remarks:

Doses / Concentrations:
500 mg/animal
Basis:
nominal in diet

No. of animals per sex per dose:

No information available:

Control animals:

yes, plain diet

Positive control(s):

None

Examinations

Tissues and cell types examined:

Bone marrow

Details of tissue and slide preparation:

Bone marrow cells were separated, concentrated and stained with Giemsa

Evaluation criteria:

No information available

Statistics:

No information available

Results and discussion

Test results

Sex:

not specified

Genotoxicity:

positive

Toxicity:

not specified

Vehicle controls validity:

not specified

Negative controls validity:

not specified

Positive controls validity:

not specified

Additional information on results:

Bone marrow cell metaphases exhibited chromosome breaks, acentric fragments, translocations, gaps and constrictions at a 7-fold rate compared to controls.

Any other information on results incl. tables

Bone marrow cell metaphases exhibited chromosome breaks, acentric fragments, translocations, gaps and constrictions at a 7-fold rate compared to controls.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information): ambiguous
Bone marrow cell metaphases exhibited chromosome breaks, acentric fragments, translocations, gaps and constrictions at a 7-fold rate compared to controls. However the interpretation of the clastogenic effect is limited by the usage of a single extremely high dose level.

Executive summary:

The potential of urea to cause chromosomal aberrations was investigated in the bone marrow of Swiss mice. Mice (number unspecified) were administered urea in the diet at a dose level of 500 mg/day for 5 days. Animals were sacrificed after a receivery period of 7 days and the bone marrow harvested. A total 300 metaphases from treated animals and untreated controls were assessed for chromosomal aberration.

A marked increase in the incidence of chromosomal aberrations was seen in the treated group (7x controls). However the dose level administered in this study is equivalent to 16 -17 g/kg bw/day and is thus far in excess of the limit dose of 1000 mg/kg bw. Signs of toxicity are not reported, but marked toxicity can be predicted at this dose level.