Determination of serum T$sub 3$ (triiodothyronine) by radioimmunoassay method

Journal Article · Mon Oct 01 04:00:00 EDT 1973 · Kaku Igaku, v. 10, no. 5, pp. 457-465

OSTI ID:4335594

Hachiya, T; Ochi, Y; Yoshimura, M; Shiomi, K; Miyazaki, T

For the determination of serum T/sub 3/ level, radioimmuaoassay using the double antibody method was developed. A specific antibody to T/sub 3/ was made in rabbit immunization with T/sub 3/ conjugated to bovine serum albumin with carbodiimide. The antibody had a cross reactivity of <0.001, <0.001, and 0.17% with L-monoiodotyrosine, L-diiodotyrosine, or L-thyroxine respectively. The incubation was performed with test serum (0.1 ml, 8-anilino1-naphthalene sulfonic acid (300 gamma )), /sup 125/I-T/sub 3/ (16 pg) and rabbit antiserum specific to T/sub 3/ in pH 7.8, 0.15 M phosphate buffer for 2 days and then the second antibody was added. By this method T/sub 3/ could be detected from 16 to 900 pg. Normal range in euthyroid subjects was 108 plus or minus 39 ng/dl. In hypothyroids it was usually 70 ng/dl and in some cases it was undetectable. In hyperthyroids it was over 200 up to 900 ng/dl. In euthyroid subjects T/sub 4//T/ sub 3/ ratio was about 121.4 plus or minus 59.8 and in hyperthyroids it was 66.8 plus or minus 26.3. However it was not calculated in hypothyroids, because T/sub 3/ was undetectable in many cases. When the hyperthyroidism patients became gradually euthyroid by the treatment with radioisotope-/sup 131/ I, increased T/sub 3/ resin sponge uptake, serum T/sub 4/ and serum T/sub 3/ became normal range gradually respectively. Also T/sub 4//T/sub 3/ ratio became normal range. However, when hyperthyroid symptom did not subside, T/sub 3/ and T/ sub 4//T/sub 3/ ratio showed still low value. The similar r esults were obtained when the hyperthyroid patient was treated by anti-thyroid drug. Therefore, the determination of T/sub 3/ and T/sub 4//T/sub 3 ratio is valuable to speculate the prognosis of hyperthyroid patients by various treatments. Serum T/sub 3/ values were determined by Dainabot Kit using dextran-coated charcoal for the separation of free and bound, and compared with the value by our double antibody method. The determined values by these two methods showed good correlation (r = 0.86). (auth)

• Research Organization: Kyoto Prefectural Univ. of Medicine
• NSA Number: NSA-29-024553
• OSTI ID: 4335594
• Journal Information: Kaku Igaku, v. 10, no. 5, pp. 457-465, Journal Name: Kaku Igaku, v. 10, no. 5, pp. 457-465; ISSN KAIGB
• Country of Publication: Japan
• Language: Japanese

Related Subjects

*TRIIODOTHYRONINE-- RADIOIMMUNOASSAY
ANTIBODIES
BLOOD SERUM
HYPERTHYROIDISM
IODINE 125
N48830* --Life Sciences--New Tracer Techniques--Other