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Related to Free Triiodothyronine: free thyroxine, FT3, Ft³, Free T4


 (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).]


(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]


(ˌtraɪ aɪˌoʊ doʊˈθaɪ rəˌnin, -aɪˌɒd oʊ-)

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)]
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.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 briefer
thyroid hormone - any of several closely related compounds that are produced by the thyroid gland and are active metabolically
References in periodicals archive ?
Abbreviations CHD: Coronary heart disease CVD: Cardiovascular disease FT3: Free triiodothyronine FT4: Free thyroxine HbA1c: Glycated hemoglobin HDL: High-density lipoprotein cholesterol LDL-C: Low-density lipoprotein cholesterol TC: Total cholesterol TG: Triglycerides T2DM: Type 2 diabetes mellitus UKPDS: United Kingdom Prospective Diabetes Study.
Fang et al., "Free triiodothyronine level correlates with myocardial injury and prognosis in idiopathic
CRP: C-reactive protein; free T3: free triiodothyronine; free T4: free thyroxine; KI: potassium iodide; MPOANCA: myeloperoxidase-anti-neutrophil cytoplasmic antibody; MTX: methotrexate; PR3-ANCA: proteinase 3-anti-neutrophil cytoplasmic antibody; PSL: prednisolone; PTU: propylthiouracil; RI (13mCi): radioisotope (13mCi); TSH: thyroid-stimulating hormone.
Liu et al., "U-shaped association between serum free triiodothyronine and recurrence of atrial fibrillation after catheter ablation," Journal of Interventional Cardiac Electrophysiology, vol.
Hormonal indices Study subject with osteoporosis Free thyroxine (pmol/L) 33.12 (21.80) Free triiodothyronine (pmol/L) 12.72 (8.51) Thyroid-stimulating 0.25 (0.03) hormone ([micro]/U/ml) Osteocalcin (ng/ml) 52.79 (15.62) 25-Hydroxyvitamin D (nmol/l) 53.60 (15.77) Parathyroid hormone (pmol/L) 5.43 (5.85) Hormonal indices Study subjects p value without osteoporosis Free thyroxine (pmol/L) 27.64 (24.40) 0.4 Free triiodothyronine (pmol/L) 7.81 (6.91) 0.02 * Thyroid-stimulating 0.41 (0.25) 0.006 * hormone ([micro]/U/ml) Osteocalcin (ng/ml) 29.85 (20.56) 0.000 * 25-Hydroxyvitamin D (nmol/l) 66.78 (16.25) 0.05 Parathyroid hormone (pmol/L) 5.57 (0.93) 0.90 * Significant p values.
At two months, mean values for free thyroxine and free triiodothyronine had decreased to a significantly greater extent, and the mean TSH value had increased to a significantly greater extent, in the selenium group than in the control group.
Fasting plasma insulin (FINS) concentration, serum level of thyroid-stimulating hormone (TSH), free triiodothyronine (FT3) concentration, free tetraiodothyronine (FT4) concentration, and thyroid peroxidase antibody (TPOAB) concentration were measured by electrochemiluminescence analyzer (Roche Diagnostics, Basel, Switzerland).
ALAT, alanine aminotransferase; ASAT, aspartate aminotransferase; BMI, body mass index; CRP, C-reactive protein; FT3, free triiodothyronine; FT4, free thyroxine; HbA1c, hemoglobin A1c; HDL, high-density lipoprotein; HOMA-IR, homeostasis model assessment-estimated insulin resistance; LDL, low-density lipoprotein; NM, not measured; TG, triglycerides; TSH, thyroid-stimulating hormone.
Serum thyroid-stimulating hormone (TSH) was 1.35 |iIU/mL (normal range: 0.35-4.94 [micro]IU/mL), free triiodothyronine (FT3) was 2.87pg/mL (normal range: 1.71-3.71 pg/mL), free thyroxine (FT4) was 1.43 ng/dL (normal range: 0.70-1.48 ng/dL), and thyroglobulin was 12.93 ng/mL (normal range: 0-32.7 ng/mL).
Serum insulin-like growth factor-1 and insulin-like growth factor-binding protein 3 levels were low, but free triiodothyronine, free thyroxine, and adrenocorticotropic hormone levels were almost normal.
Thyroid function tests were consistent with a hyperfunctioning thyroid state: thyrotropin (TSH) < 0,005 IU/mL (normal range 0,358-3,740 IU/mL), free thyroxine (fT4) 4,97 ng/ dL (normal range 0,76-1,46 ng/dL), free triiodothyronine (fT3) 27,58 pg/mL (normal range 2,18-3,98 pg/mL), with positive anti-thyroid autoantibodies: thyroid peroxidase antibodies (anti-TPO) > 3340 IU/mL (normal range 0-100 IU/ mL), thyroglobulin antibodies (anti-Tg) > 24400 IU/mL (normal range 0-344 IU/mL), and thyrotropin receptor antibodies (TRAbs) 14,3 IU/mL (normal range < 1,2 IU/mL).
[20] Higher free triiodothyronine levels may be one of the cause for high PP in overweight and obese adult individuals.