Effects of Chronic Treatment of Intact and Hypophysectomized Rats with Thyroid-Stimulating Hormone on the Metabolism of [35S]Methimazole and [36S]Propylthiouracil
JEAN F. H. LEES, W.D. Alexander
Abstract
JEAN F. H. LEES, W.D. Alexander
Abstract
Chronic treatment of intact rats with various doses of TSH increased the thyroidal 35S accumulation after single doses of [35S]methimazole (MMI) and [35S]propylthiouracil (PTU). However, no effect on the intrathyroidal breakdown of the drugs was observed. Thus absolute thyroidal levels of unmetabolized MMI and PTU were increased by factors of up to 2 and 3, respectively, compared to the control groups. Simultaneous decreases in the levels of thyroidal total iodine were observed. Hypophysectomized rats showed a marked inhibition of both thyroidal accumulation and oxidation of [35S]-MMI but TSH treatment of hypophysectomized rats restored the accumulation and oxidation to sham-operated and control group levels. The results show that in rats TSH has an important role in the control of thyroidal levels of antithyroid drugs currently used in the treatment of hyperthyroidism.
OpenAlex reports 6 citations for this work. Citation counts describe recorded attention and do not establish research quality.
A contribution statement is not available in the OpenAlex record.
Method details are not available in the OpenAlex metadata.
Findings are not separately available in the OpenAlex metadata.
Limitations are not available in the OpenAlex metadata.
Application details are not available in the OpenAlex metadata.
Chronic treatment of intact rats with various doses of TSH increased the thyroidal 35S accumulation after single doses of [35S]methimazole (MMI) and [35S]propylthiouracil (PTU). However, no effect on the intrathyroidal breakdown of the drugs was observed. Thus absolute thyroidal levels of unmetabolized MMI and PTU were increased by factors of up to 2 and 3, respectively, compared to the control groups. Simultaneous decreases in the levels of thyroidal total iodine were observed. Hypophysectomized rats showed a marked inhibition of both thyroidal accumulation and oxidation of [35S]-MMI but TSH treatment of hypophysectomized rats restored the accumulation and oxidation to sham-operated and control group levels. The results show that in rats TSH has an important role in the control of thyroidal levels of antithyroid drugs currently used in the treatment of hyperthyroidism.
Key concepts: Propylthiouracil, Internal medicine, Endocrinology, Methimazole, Antithyroid agent, Thyroid, Iodine, Hormone