Ammonium bromide

Immunotoxicity

Description of key information

Analysis of the expression of the proliferating cell nuclear antigen (PCNA) was used to determine the presumed hyperplastic character of morphological changes in the rat thyroid evoked by bromide administration. Male rats were fed by a diet containing additional bromide for 16, 66 or 133 days. The thyroids of treated animals showed activation of growth of the follicular component as well as diffuse and focal microfollicular rearrangement of the parenchyma with higher follicular cells accompanied by a decrease of the amount of colloid even at low bromine concentrations (10-100 mg Br-/L drinking water). The PCNA-LI index was significantly higher in bromide exposed animals and correlated well with the histological changes, with bromide concentration and with an increased mitotic activity of the follicular cells.

Key value for chemical safety assessment

Effect on immunotoxicity: via oral route

Link to relevant study records

Reference

Endpoint:

immunotoxicity: oral

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Qualifier:

no guideline followed

Principles of method if other than guideline:

No guideline followed

GLP compliance:

no

Species:

rat

Strain:

Wistar

Sex:

male

Route of administration:

oral: drinking water

Vehicle:

water

Duration of treatment / exposure:

16, 66 and 133 days

Remarks:

Doses / Concentrations:
0, 10, 50 and 100 mg Br-/l drinking water, 16 and 66 days
Basis:
nominal in water

Remarks:

Doses / Concentrations:
0, 100, 200 and 400 mg Br-/l drinking water, 133 days
Basis:
nominal in water

No. of animals per sex per dose:

10

Control animals:

yes, concurrent vehicle

Basis for effect level:

other: see 'Remark'

Remarks on result:

not measured/tested

Remarks:

Effect level not specified (migrated information)

Conclusions:

Analysis of the expression of the proliferating cell nuclear antigen (PCNA) was used to determine the presumed hyperplastic character of morphological changes in the rat thyroid evoked by bromide administration. Male rats were fed by a diet containing additional bromide for 16, 66 or 133 days. The thyroids of treated animals showed activation of growth of the follicular component as well as diffuse and focal microfollicular rearrangement of the parenchyma with higher follicular cells accompanied by a decrease of the amount of colloid even at low bromine concentrations (10-100 mg Br-/L drinking water). The PCNA-LI index was significantly higher in bromide exposed animals and correlated well with the histological changes, with bromide concentration and with an increased mitotic activity of the follicular cells.

Additional information

Analysis of the expression of the proliferating cell nuclear antigen (PCNA) was used to determine the presumed hyperplastic character of morphological changes in the rat thyroid evoked by bromide administration. Male rats were fed by a diet containing additional bromide for 16, 66 or 133 days. The thyroids of treated animals showed activation of growth of the follicular component as well as diffuse and focal microfollicular rearrangement of the parenchyma with higher follicular cells accompanied by a decrease of the amount of colloid even at low bromine concentrations (10-100 mg Br-/L drinking water). The PCNA-LI index was significantly higher in bromide exposed animals and correlated well with the histological changes, with bromide concentration and with an increased mitotic activity of the follicular cells.