Promoting effect of 2,4-diaminoanisole sulfate on rat thyroid carcinogenesis.
Two experiments were conducted to examine the effects of 2,4-diaminoanisole sulfate (2,4-DAAS) on thyroid function and carcinogenesis in male Wistar rats. In experiment 1, feeding with 2,4-DAAS resulted in significantly elevated levels of thyroid stimulating hormone (TSH), reduced thyroxine (T4) and triiodothyronine (T3) in the serum, although the latter had almost recovered to normal levels by week 6. However, skin application did not affect serum levels. In experiment 2, administration of 0.5% 2,4-DAAS in the diet for 19 weeks, a week after a single 210 mg/100 g body weight i.p. injection of N-bis(2-hydroxypropyl)nitrosamine (DHPN), significantly increased the incidence and numbers of preneoplastic lesions (focal hyperplasia), adenomas and carcinomas developing in the thyroid gland. Histologically, brown pigment was usually observed within follicular epithelial cells in non-tumorous regions, but not in the tumors themselves.
Kitahori
Y
Y
1st Department of Pathology, Nara Medical University, Kashihara, Japan.
Ohshima
M
M
Matsuki
H
H
Konishi
N
N
Hashimoto
H
H
Minami
S
S
Thamavit
W
W
Hiasa
Y
Y
D000236:Adenoma / Q000139:chemically induced; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D002273:Carcinogens; D002277:Carcinoma / Q000139:chemically induced; D003043:Cocarcinogenesis; D006202:Hair Dyes / Q000633:toxicity*; D006203:Hair Preparations / Q000633:toxicity*; D006965:Hyperplasia / Q000139:chemically induced; D008297:Male; D009929:Organ Size / Q000187:drug effects; D010655:Phenylenediamines / Q000633:toxicity*; D051381:Rats; D011919:Rats, Inbred Strains; D013961:Thyroid Gland / Q000473:pathology; D013964:Thyroid Neoplasms / Q000139:chemically induced* / Q000473:pathology; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D014284:Triiodothyronine / Q000097:blood
D002273:Carcinogens; D006202:Hair Dyes; D006203:Hair Preparations; D010655:Phenylenediamines; D014284:Triiodothyronine; C007294:4-methoxy-3-phenylenediamine; D013972:Thyrotropin; D013974:Thyroxine