Subchronic thyroid toxicity evaluation of 4,4'-methylenebis(N,N'-dimethyl)aniline in Fischer 344 rats.
J Toxicol Environ Health A
; 75(11): 637-48, 2012.
Article
em En
| MEDLINE
| ID: mdl-22712849
ABSTRACT
Female F344 rats were exposed to 4,4'-methylenebis(N,N'-dimethyl)aniline (MDA) by dietary feed at concentrations of 0, 50, 200, 375, 500, or 750 ppm for 5 d, 2 wk, 4 wk, and 13 wk duration. Endpoints evaluated included clinical observations, body weights, thyroid weights, serum thyroid hormones, blood MDA, gross pathology, and thyroid histopathology. There were no MDA exposure-related clinical signs of toxicity. Mean body weight decreased 5% compared to control in the 750 ppm group during study wk 6 through 13. Serum TSH increased and serum T4 and T3 levels decreased with increasing feed concentrations of MDA and time of exposure. Thyroid weight increases were both concentration- and exposure time-dependent and statistically significant at ≥375 ppm. Incidence and severity of decreased colloid, follicular cell hypertrophy and follicular cell hyperplasia were also related to MDA concentration and exposure time. A no-observed-adverse-effect level (NOAEL) of 200 ppm was selected based on the statistically significant increase in incidence of follicular cell hyperplasia at concentrations ≥375 ppm.
Texto completo:
1
Bases de dados:
MEDLINE
Assunto principal:
Glândula Tireoide
/
Indicadores e Reagentes
/
Compostos de Anilina
Idioma:
En
Revista:
J Toxicol Environ Health A
Assunto da revista:
SAUDE AMBIENTAL
/
TOXICOLOGIA
Ano de publicação:
2012
Tipo de documento:
Article
País de afiliação:
Estados Unidos