[Effect of disordered thyroid function on the realization of the transplacental carcinogenic action of N-nitrosomethylurea in 1st- and 2d-generation rats].
The F1 rats subjected to the influence of N-nitrosomethylurea (NMU) in dose of 20 mg/kg on the 21 day gestation as a result of postnatal disturbances of the thyroid function induced by long administration of thyroxin (3 mg/100 g, daily), methylthiouracil (MTU; 0.1% solution in tap water) or thyroidectomy have shown a decreased incidence of the nervous system tumours, but not of the kidney tumours, i. e. sites typical of NMU transplacental carcinogenesis. At the same time the NMU transplacental effect increased thyroid carcinogenesis, induced by the MTU postnatal application, which manifested in the increased incidence of malignant tumours of this site. The carcinogenic effect was observed in F2 rats, while some of them developed tumours of the nervous system (14.9%) and kidney (8.5%) but with lower incidence than in F1 (35.4; 14.1%, respectively). The same modifying factors (thyroxin, thyroidectomy, MTU) employed under the same conditions produca similar effect on carcinogenesis in F2 animals.
D000818:Animals; D005260:Female; D008770:Methylnitrosourea / Q000633:toxicity*; D008779:Methylthiouracil / Q000494:pharmacology; D009374:Neoplasms, Experimental / Q000139:chemically induced* / Q000503:physiopathology; D010920:Placenta; D011247:Pregnancy; D051381:Rats; D013961:Thyroid Gland / Q000187:drug effects / Q000503:physiopathology*; D013965:Thyroidectomy; D013974:Thyroxine / Q000494:pharmacology
D008770:Methylnitrosourea; D013974:Thyroxine; D008779:Methylthiouracil
Vliianie narusheniia funktsii shchitovidnoĭ zhelezy na realizatsiiu transplatsentarnogo kantserogennogo deĭstviia N-nitrozometilmocheviny u krys pervogo i vtorogo pokoleniĭ.