释义 |
triiodothyronine
tri·i·o·do·thy·ro·nine T0357350 (trī′ī-ō′dō-thī′rə-nēn′, -ī-ŏd′ō-)n. Abbr. T3 An iodine-containing hormone, C15H12I3NO4, produced by the thyroid gland and similar to but more potent than thyroxine. A synthetic form (liothyronine) is used in the treatment of hypothyroidism. [tri- + iodo- + thyronine, an amino acid (thyr(o)- + -on(e) + -ine).]triiodothyronine (ˌtraɪaɪˌəʊdəʊˈθaɪrəˌniːn) n (Biochemistry) an amino acid hormone that contains iodine and is secreted by the thyroid gland with thyroxine, to which it has a similar action. Formula: C15H12I3NO4[C20: from tri- + iodo- + thyro- + -ine2]tri•i•o•do•thy•ro•nine (ˌtraɪ aɪˌoʊ doʊˈθaɪ rəˌnin, -aɪˌɒd oʊ-) n. a thyroid hormone, C15H12I3NO4, similar to thyroxine but more potent: preparations of it used in treating hypothyroidism. [1950–55; tri- + iod(ine) + -o- + thyronine (perhaps derivative, with -one, of thyroxine)] ThesaurusNoun | 1. | triiodothyronine - thyroid hormone similar to thyroxine but with one less iodine atom per molecule and produced in smaller quantity; exerts the same biological effects as thyroxine but is more potent and brieferliothyronine, Tthyroid hormone - any of several closely related compounds that are produced by the thyroid gland and are active metabolically |
Triiodothyronine
Triiodothyronine (3,5,3’-triiodothyronine), an animal and human hormone formed in the follicles of the thyroid gland by the oxidative condensation of monoiodotyrosine and diiodotyro-sine. 
Like the other thyroid hormone, thyroxine, triiodothyronine has a multiple, varied effect on the organism and on the organism’s growth, differentiation, and metabolism. It is secreted into the blood in significantly smaller amounts than thyroxine, but its effect on metabolism is more rapid, since it is less strongly bound to specific plasma proteins and thus enters the tissue fluid and cells more easily. triiodothyronine
triiodothyronine [tri″i-o″do-thi´ro-nēn] a thyroid hormone that contains iodine" >iodine and is liberated from thyroglobulin" >thyroglobulin by hydrolysis. It has several times the biologic activity of thyroxine.free triiodothyronine the fraction of triiodothyronine in the serum that is not bound to a binding protein.triiodothyronine resin uptake test a thyroid function test, measuring how many sites on thyroxine-binding globulin (TBG) are occupied by endogenous triiodothyronine (T3) and how many sites remain available. An excess of radioactive exogenous triiodothyronine is added to the sample, followed by the addition of a resin that also binds T3. A portion of the radioactive T3 binds to sites on TBG not already occupied by endogenous thyroid hormones, and the remainder binds to the resin. The amount of labeled hormones bound to the resin (the uptake" >triiodothyronine resin uptake) can be subtracted from the total that was added and the remainder is the amount that bound to the unoccupied binding sites on the thyroxine-binding globulin.triiodothyronine (trī′ī-ō′dō-thī′rə-nēn′, -ī-ŏd′ō-)n. A thyroid hormone, C15H12I3NO4, similar to thyroxine but more potent, used in the treatment of hypothyroidism.triiodothyronine T3, 3,5,3´,-´triiodothyronine A hormone formed by removing an iodine ion from the chemical parent thyroxine–T4, which occurs in the liver and kidney; in general, the T3 and T4 serum levels rise and fall together with certain exceptions–eg, T3 thyrotoxicosis, in which T4 and free T4 values are in the normal range; most T3 is not bound to a carrier protein in the circulation ↑ in Hyperthyroidism–T3 thyrotoxicosis, pregnancy, and therapy with clofibrate,–oral contraceptives–progestins, estrogens, methadone, perphenazine ↓ in Euthyroid sick syndrome, ↑ free fatty acids, hypothyroidism, malnutrition, or therapy with corticosteroids, ethionamide, heparin, iodides, lithium, methimazole, phenylbutazone, phenytoin, propranolol, propylthiouracil, reserpine, salicylates, sulfonamides, testosterone, tolbutamide; Pts with T3 thyrotoxicosis are clinically heterogeneous and lack distinctive signs and Sx, comprising 4% of hyperthyroid Pts due to Graves' disease, toxic nodular goiter and thyroid adenomas and a higher percentage of hyperthyroidism in regions with lower levels of iodine Ref value 0.92-2.46 nmol/L; 60-160 ng/dL. See Thyroxine–T4, Thyroxine-binding globulin, TSH.AcronymsSeeT3triiodothyronine
Synonyms for triiodothyroninenoun thyroid hormone similar to thyroxine but with one less iodine atom per molecule and produced in smaller quantitySynonymsRelated Words |