Evaluation of thyroid gland activity by hormone assays and flow cytometry in rats.
Spontaneous variations in the activity of thyroids and changes induced by methimazole, phenobarbital and 2,4--diaminoanisole sulfate were assessed in rats by repeated measurements of serum T3, T4 and TSH concentrations and cell cycle analysis in isolated nuclei of the thyroids. Methimazole caused a decrease in T3 and T4, and elevation in TSH, reduction of cells in G1 and increase in the percentage of cells in S and G2 phases. With phenobarbital T4 concentrations were decreased, but a mitogenic effect was only seen after 8 weeks. With 2,4-diaminoanisole sulfate the most prominent change observed was a decrease in T3 concentrations.
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Institute of Toxicology, Swiss Federal Institute of Technology, Schwerzenbach.
D000818:Animals; D013956:Antithyroid Agents / Q000494:pharmacology*; D002453:Cell Cycle / Q000187:drug effects; D005434:Flow Cytometry; D008297:Male; D008713:Methimazole / Q000494:pharmacology; D010634:Phenobarbital / Q000494:pharmacology; D010655:Phenylenediamines / Q000494:pharmacology; D051381:Rats; D013961:Thyroid Gland / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D013972:Thyrotropin / Q000097:blood*; D013974:Thyroxine / Q000097:blood*; D014284:Triiodothyronine / Q000097:blood*
D013956:Antithyroid Agents; D010655:Phenylenediamines; D014284:Triiodothyronine; D008713:Methimazole; C007294:4-methoxy-3-phenylenediamine; D013972:Thyrotropin; D013974:Thyroxine; D010634:Phenobarbital