Potassium iodide

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in mammalian cells

Remarks:

Type of genotoxicity: gene mutation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: TThe published literature fulfilled basically scientific principles without GLP compliance statement.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1980

Materials and methods

Test guideline

Test guideline 1

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 476 (In Vitro Mammalian Cell Gene Mutation Test)

Test guideline 2

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method B.21 (In Vitro Mammalian Cell Transformation Test)

GLP compliance:

no

Remarks:

old publication

Type of assay:

mammalian cell gene mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

iodide in potassium

IUPAC Name:

iodide in potassium

Details on test material:

Potassium iodide was purchased from J.T. Baker (Phillipsburg, N.J.).

Method

Species / strain

Species / strain 1

Species / strain / cell type:

mouse lymphoma L5178Y cells

Details on mammalian cell type (if applicable):

The l5178Y mouse-lymphoma cells were originally derived from a methylcholanthrene induced lymphoma (Fischer, 1958) and have subsequently been selected for heterozygous activity at the thymidine kinase locus (Give et al., 1972, 1973, 1975). The l5178Y cell line used in our studies was kindly supplied by Mr. Ken Palmer (Food and Drug Administration, Washington, D.C).

Additional strain / cell type characteristics:

not applicable

Species / strain 2

Species / strain / cell type:

other: BALB/c 3T3

Details on mammalian cell type (if applicable):

Balb/c 3T3 cells (Dr. D. Brusick, litton Blonetics, Kensington, Md.), derived from done A31 of the Balb/c 3T3 1ine, were used for the transformation studies. The cells were grown in Eagle's Minimal Essential Medium with Eagle's- Salts (EMEM), supplemented with 10% fetal calf serum and 1 % 200 mM glutamine (Gibco). Stock cultures were maintained at 75% confluence. The maintenance medium was EMEM with 5% fetal calf serum.

Additional strain / cell type characteristics:

other:

Metabolic activation:

without

Metabolic activation system:

Iodide is small ion, so the metabolic actication system is unnecessary to the test

Test concentrations with justification for top dose:

Mutagenicity test:
100 μg/ml, 500 μg/ml, I mg/ml; 5 mg/ml, 10 mg/ml.

Transformation test:
100 μg/ml, 500 μg/ml, I mg/ml; 5 mg/ml, 10 mg/ml.

Controls

Controls 1

Untreated negative controls:

yes

Remarks:

media

Negative solvent / vehicle controls:

no

Remarks:

no hazard vehicle used

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

ethylmethanesulphonate

Remarks:

Migrated to IUCLID6: In report it was named EMS

Controls 2

Positive controls:

yes

Positive control substance:

N-dimethylnitrosamine

Remarks:

Migrated to IUCLID6: In report it was named DMN

Controls 3

Positive controls:

yes

Positive control substance:

N-ethyl-N-nitro-N-nitrosoguanidine

Remarks:

Migrated to IUCLID6: In report it was named MNNG

Results and discussion

Test results

Test results 1

Species / strain:

mouse lymphoma L5178Y cells

Metabolic activation:

without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

other: not applicable

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 2

Species / strain:

other: BALB/c 3T3

Metabolic activation:

without

Genotoxicity:

other: not applicable

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Remarks:

negative

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: other: no data

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

Table 1  Mutagenicity of iodide in the L5178Y Test System

Mutagenicity of iodide in the L5178Y Test System
Compound	concentration	.Mutational Frenquency
Iodide (KI solution)	10 mg/ml	1.0
	5 mg/ml	0.76
	1 mg/ml	1.33
	500μg/ml	1.67
	100 μg/ml	1.0
Negative control (Media)		1.0
EMS	500 μg/ml	12.0
MNNG	5 μg/ml	15.0

Table 2  Effects of iodide on the Transformation of Balb/c 313 Cells

Effects of iodide on the Transformation of Balb/c 313 Cells
Compound	concentration	.# of foci
iodide	10 mg/ml	0.33
	5 mg/ml	2.0
	1 mg/ml	0.61
	500μg/ml	0.61
	100 μg/ml	0.83
Negative control (Media)		1.22
MNNG	5 μg/ml	7.50

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative No effects can be found in either mutagenicity or BALB/c 3T3 cell transformation assays.

Solutions of potassium iodide at concentrations of 0.1–10 mg/ml did not cause mutagenic effects in L5178Y mouse lymphoma cells or transforming activity in Balb/c3T3 cells grown in culture.

Executive summary:

The mutagenic potential to iodide (in potassium iodide ) was studied using the L5178Y mouse (TK+/-) lymphoma assay. The established mutagens ethylmethanesulphonate (EMS) and dimethylnitrosamine (DMN) were highly active in this assay, whereas iodide (KI) was inactive. Using the BALB/c 3T3transformation assayweassessed the transformational capacities of these same agents and the positive mutagen N-ethyl-N-nitro-N-nitrosoguanidine(MNNG). All concentrations of the iodide tested were inactive in this assay. It can be concluded that KI did not possess any biologically significant mutagenic or cell transforming ability.