Human lymphocyte binding and deiodination of thyroid hormones in relation to thyroid function.
The human lymphocyte has been investigated regarding its function as a thyroid hormone target cell. Binding and deiodination of the thyroid hormones were determined after simultaneous incubation of 131I-labelled L-thyroxine (131I-T4) and 125I-labelled L-triiodothyronine (125I-T3) with lymphocytes from healthy subjects, from hyperthyroid and primary hypothyroid patients before and after treatment. The mean percentages of binding, 8.0 +/- 0.5 (mean +/- SEM) for 131I-T4, and 9.7 +/- 0.4 for 125I-T3 in the control group, were increased in the hyperthyroids to 10.1 +/- 0.4 and 12.7 +/- 0.6 respectively, and in the hypothyroids to 10.9 +/- 0.7 and 12.8 +/- 0.6. All elevated values returned to normal with successful treatment. The mean percentage of deiodination, 12.0 +/- 1.7 for 131I-T4, and 6.5 +/- 0.9 for 125I-T3 in the control group, showed a threefold increase in the hyperthyroid patients, to 35.9 +/- 3.2 and 20.2 +/- 1.9 respectively and remained unaltered in the hypothyroid patients. The values of successfully treated hyperthyroid patients were normal and those of the treated hypothyroid patients below normal.
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D006801:Humans; D006980:Hyperthyroidism / Q000097:blood* / Q000188:drug therapy; D007037:Hypothyroidism / Q000097:blood* / Q000188:drug therapy; D007457:Iodine Radioisotopes; D008214:Lymphocytes / Q000378:metabolism*; D008875:Middle Aged; D011956:Receptors, Cell Surface / Q000187:drug effects; D013268:Stimulation, Chemical; D013696:Temperature; D013972:Thyrotropin / Q000494:pharmacology / Q000627:therapeutic use; D013974:Thyroxine / Q000097:blood*; D014284:Triiodothyronine / Q000097:blood*
D007457:Iodine Radioisotopes; D011956:Receptors, Cell Surface; D014284:Triiodothyronine; D013972:Thyrotropin; D013974:Thyroxine