title: 2,4-diaminoanisole-induced thyroid pigmentation in rats inhibited by m-phenylenediamine.
abstract: The effect of the carcinogenic hair dye component 2,4-diaminoanisole (2,4-DAA) on thyroid and pituitary morphology was studied. Heavy pigmentation of the hypertrophied thyroid epithelium was present when the animals were fed with 2,4-DAA for 6 weeks. Another hair dye component m-phenylenediamine (m-PDA), which lacks the methoxy group, and which is not carcinogenic, prevented the dark pigmentation of the thyroid epithelium caused by 2,4-DAA, but had only a slight effect on the hypertrophy of the gland. In the pituitary gland of 2,4-DAA-fed animals only a few aldehyde fuchsin positive thyrotrope cells were present. When 2,4-DAA and m-PDA were fed simultaneously, the number of hypertrophied chromophobic cells was greatly increased and the aldehyde fuchsin-positive cells were practically absent.
mesh_terms: D000818:Animals; D000840:Anisoles / Q000037:antagonists & inhibitors / Q000494:pharmacology; D005260:Female; D010655:Phenylenediamines / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D010859:Pigmentation Disorders / Q000473:pathology; D010902:Pituitary Gland / Q000166:cytology*; D051381:Rats; D013194:Staining and Labeling; D013961:Thyroid Gland / Q000166:cytology*
chemical_list: D000840:Anisoles; D010655:Phenylenediamines; C007294:4-methoxy-3-phenylenediamine