Potassium iodate

Toxicity to reproduction

Administrative data

Endpoint:

two-generation reproductive toxicity

Remarks:

based on test type (migrated information)

Type of information:

migrated information: read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

1984

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other:

Principles of method if other than guideline:

Potassium iodide (KI) was fed to male and female rats before and during breeding, to females only during gestation and lactation, and to their offspring after weaning (day 21 after birth) through to day 90, at levels of 0, 0.025, 0.05 or 0.1% (w/w) of the diet. Dams in a fifth group (positive controls) were given 4 mg/kg ip of the anti-mitotic/cytotoxic drug 5-azacytidine on day 17 of gestation

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Potassium iodide

EC Number:

231-659-4

EC Name:

Potassium iodide

Cas Number:

7681-11-0

Molecular formula:

IK

IUPAC Name:

potassium iodide

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

Male and female Sprague-Dawley rats (200-240 g; Laboratory Supply Co., Indianapolis, IN) were obtained.

Administration / exposure

Route of administration:

oral: feed

Type of inhalation exposure (if applicable):

not specified

Vehicle:

unchanged (no vehicle)

Details on exposure:

Male and female Sprague-Dawley rats (200-240 g; Laboratory Supply Co., Indianapolis, IN) were acclimatized to the laboratory for 5 days before assignment to groups given diets (Purina rat chow meal) supplemented with 0 (two control groups), 0.025, 0.05 or 0.1% (w/w) potassium iodide.
Negativecontrol dams received no treatment.
Positive-control dams were given two ip injections of 2 mg/kg of S-azacytidine on day 17 of gestation.
Dietary treatments were given continuously to both males and females for 14 days before mating and for 1-14 days during breeding, and to females only during gestation (22 days) and lactation (21 days). After weaning, the offspring were given dietary potassium iodide, at the level their parents had received, throughout the remainder of the experiment.

Duration of treatment / exposure:

17-90 days

Doses / concentrations

Remarks:

Doses / Concentrations:
0, 0.025, 0.05 or 0.1% (w/w)
Basis:
nominal in diet

Control animals:

yes

Positive control:

yes

Examinations

Parental animals: Observations and examinations:

KI delayed auditory startle at the two highest doses, delayed olfactory orientation to the home-cage scent at the middle dose and decreased female running-wheel activity at all dose levels. In rats killed on day 90 after birth KI reduced brain and body weight at a dose of 0.1% of the diet, and reduced body but not brain weight at a dose of 0.05% of the diet.

Results and discussion

Results: P0 (first parental generation)

Details on results (P0)

A reduction in male (P < 0.01), but not female, food consumption was found in the 0. 1% potassium iodide group prior to breeding, but this reduction
resulted in only a marginal decrease in body weight (P < 0.09). No effects were found on maternal food consumption or body weight during gestation

Effect levels (P0)

Dose descriptor:

other: Not available

Sex:

male/female

Basis for effect level:

other: Effect level not known

Remarks on result:

not measured/tested

Remarks:

Effect level not specified (migrated information)

Overall reproductive toxicity

Reproductive effects observed:

not specified

Any other information on results incl. tables

Mortality of offspring from rats fed 0-0.1~ potassium iodide in the diett
Mortality (%)
			Potassium iodide groups
Age (days):	Negative control	Positive control	0.025%	0.05%	0.1%
0-1	0.0	12.3"*	0.9	0.5	6.0**
2-24	13.1	28.6**	5.1 *	14.8	21.9*
25-90	1.0	0.0	1.4	4.0	5.2

tArter weaning (day 21) offspring were fed potassium iodide in their diet at the same level fed to their parents.Birth date considered to be day 0.

§Positive-control dams received two ip injections of 5-azacytidine on day 17 of gestation.

Values marked with asterisks differ significantly from the corresponding negative-control value:*P < 0.05; **P < 0.01

Applicant's summary and conclusion

Conclusions:

All offspring were reared by their natural dams and were evaluated blind with respect to treatment in a battery of standardized behavioural tests between 3 and 90 days of age. KI produced no significant reductions in parental body weight or food consumption, though it significantly reduced litter size and increased offspring mortality at the highest dose, and decreased weight gain at the two highest doses throughout the first 90 days after birth.

Executive summary:

Potassium iodide produced no significant reductions in parental body weight or food consumption, though it significantly reduced litter size and increased offspring mortality at the highest dose, and decreased weight gain at the two highest doses throughout the first 90 days after birth.

In rats killed on day 90 after birth KI reduced brain and body weight at a dose of 0.1% of the diet, and reduced body but not brain weight at a dose of 0.05% of the diet. No significant effect was found on absolute or relative thyroid weight at 90 days of age.