The effect of overheating on the oxygen consumption of rats of various levels of thyroid function

Hypothyroid, normal and 'thyrotoxic' rats were overheated under standardized conditions, and their rectal temperatures and oxygen consumption were measured. During 30–60 min. of heating, body temperature and oxygen consumption rose more slowly in the hypothyroid animals and more rapidly in the 'thyrotoxic' ones as compared with normal rats. It was also found that, for the same induced increase in body temperature, the oxygen consumption of the hypothyroid rats rose less and that of the 'thyrotoxic' rats more than that of the normal animals.

Effect of graded doses of carbimazole and propylthiouracil on the synthesis of the thyroid hormones

The effect of graded doses of carbimazole on hormonal synthesis in the thyroid gland was studied in the rat, and compared with that of graded doses of propylthiouracil. The synthesis of thyroxine and triiodothyronine was totally inhibited by 3–5 mg of carbimazole daily; at this dose the ratio was the same as for untreated controls. A dose of 1–3 1− mg of propylthiouracil also inhibited the synthesis of thyroxine and triiodothyronine, but at this dose the ratio was much lower than for the controls. The dose of carbimazole that inhibits the formation of thyroxine and triiodothyronine seems to have little effect on the icdination of the tyrosine radicals and on the formation of mono- and diiodotyrosine.

Fractionated 131-I therapy in large toxic goitres

The results of, and complications associated with, 131I therapy in 123 cases of hyperthyroidism with large nodular toxic goitre are reported. The results improved with the size of the first dose, but the frequency of early reactions also increased with the dose.

Fractionated radioiodine therapy is recommended in the management of patients with large nodular toxic goitre and tracheal compression or severe hyperthyroidism. The results for 34 patients treated by this method and followed up for at least one year are reported.

Resin uptake of 131-I-labelled triiodothyronine after administration of iodine

The effect of administering large doses of inorganic and organic iodine on the PBI, thyroidal uptake of radioiodine and the resin sponge uptake of 131I triiodothyronine has been studied on 38 euthyroid subjects. The resin sponge uptake is unaffected by large doses of iodine, which depress the thyroidal uptake and affect the result of the PBI test.