Reaction products of sodium glucoheptonate with zinc sulfate and sodium hydroxide

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1974

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods with acceptable restrictions

Data source

Reference

Reference Type:

publication

Title:

Mutagenicity of chromates in bacteria and its relevance to chromate carcinogenesis

Author:

Venitt S, Levy LS

Year:

1974

Bibliographic source:

Nature 250, 493 - 495 (09 August 1974)

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

E.coli WP2 strains were grown overnight in nutrient broth at 37° C and diluted 1:50 in enriched M9 medium. Cells were collected during mid-logarithmic phase. 5 x 10E7 bacteria were spread on agar plates containing M9 medium, 0.4% (w/v) casamino-acids and 1 µg/mL L-trypophan. Test compounds were dissolved in deionised water, filter-sterilised, and 5 µL applied to the centre of each plate. Pre-existing revertants were assayed on agar plates containing M9 medium. Plates were incubated at 37° C and the maximum yield of mutants (that is, revertants to tryptophan prototrophy) was obtained 4-5 d after plating.

GLP compliance:

no

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Zinc

EC Number:

231-175-3

EC Name:

Zinc

Cas Number:

7440-66-6

IUPAC Name:

zinc

Test material form:

not specified

Specific details on test material used for the study:

not specified

Method

Target gene:

trpE locus

Species / strain

Species / strain 1

Species / strain / cell type:

E. coli WP2

Species / strain 2

Species / strain / cell type:

E. coli WP2 uvr A

Species / strain 3

Species / strain / cell type:

E. coli WP2

Remarks:

exrA

Metabolic activation:

without

Test concentrations with justification for top dose:

not specified

Vehicle / solvent:

deionised water, filter-sterilised

Controls

Untreated negative controls:

not specified

Negative solvent / vehicle controls:

yes

True negative controls:

not specified

Positive controls:

not specified

Positive control substance:

not specified

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation)

- Cell density at seeding (if applicable): 5x10E7

DURATION
- Preincubation period: overnight
- Exposure duration: 4-5 days

Statistics:

t-test

Results and discussion

Test results

Test results 1

Species / strain:

E. coli WP2

Metabolic activation:

without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

not examined

Test results 2

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

not examined

Test results 3

Species / strain:

E. coli WP2

Remarks:

E. coli WP2 exrA

Metabolic activation:

without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

not examined

Applicant's summary and conclusion

Conclusions:

Zinc salts were negative in three different E. coli strains.

Executive summary:

The mutagenicity of zinc salts on three different E. coli strains was tested in a bacterial reverse mutation assay on agar plates. Zinc salts were negative in all three strains tested.