FD&C Red No. 105 (Rose Bengal B) neutralizes the thyroid tumor promoting effect of iodine-deficient diet in rats.
The effect of 3,4,5,6-tetrachloro-2',4',5',7'-tetraiodo-fluorescein sodium salt (Rose Bengal B or FD&C Red No. 105, molecular weight 1017.6) on the thyroid of rats treated with N-bis(2-hydroxypropyl)-nitrosamine (DHPN) and iodine-deficient (I-def) diet is studied. Six-week-old male F344 rats were divided into seven groups (20 each) and given a single subcutaneous injection of DHPN (2800 mg/kg body wt.). From week 2 to 20, I-def diet was given in combination with either FR105 (1.25, 5.0, or 20 mg/l) or potassium iodide (KI, 12.5, 50.0 or 200 micrograms/l) in drinking water. As a result, an amount of 1.25 mg/l of FR105 was slightly more effective than 200 micrograms/l of KI in terms of inhibition of the effect of I-def diet on thyroid weight, morphology, thyroid-related hormones and thyroid tumor development. It was calculated that 1 mumol/l of FR105 was slightly more potent than 1 mumol/l of iodide ion. As each FR105 molecule has four iodide residues, at least 25% of total iodide residues were calculated to be utilized by the rats given I-def diet.
Kanno
J
J
Department of Pathology, Faculty of Medicine, Tokyo Medical and Dental University, Japan.
Goda
Y
Y
Sato
K
K
Yoshihira
K
K
Hayashi
Y
Y
D000818:Animals; D002273:Carcinogens / Q000145:classification / Q000494:pharmacology* / Q000633:toxicity; D004347:Drug Interactions; D007454:Iodides / Q000633:toxicity; D007455:Iodine / Q000172:deficiency*; D008297:Male; D011193:Potassium Iodide / Q000494:pharmacology; D051381:Rats; D011916:Rats, Inbred F344; D012395:Rose Bengal / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology / Q000633:toxicity; D013964:Thyroid Neoplasms / Q000139:chemically induced* / Q000209:etiology / Q000517:prevention & control
D002273:Carcinogens; D007454:Iodides; D011193:Potassium Iodide; D012395:Rose Bengal; C048837:Rose Bengal B; D007455:Iodine