A radioimmunoassay for measurement of thyroxine sulfate
- Univ. of California Center for the Health Sciences, Los Angeles (United States)
A highly sensitive, specific, and reproducible RIA has been developed to measure T[sub 4] sulfate (T[sub 4]S) in ethanol extracts of serum. rT[sub 3] sulfate (rT[sub 3]S) cross-reacted 7.1%, and T[sub 3]S cross-reacted 0.59% in the RIA; T[sub 4], T[sub 3], rT[sub 3] and 3,3[prime]-diiodothyronine cross-reacted 0.004% or less. The recovery of nonradioactive T[sub 4]S added to serum averaged 95%. The detection threshold of the RIA was 18 pmol/L. The coefficient of variation averaged 6.9% within an assay and 12% between assays. T[sub 4]S was bound by T[sub 4]-binding globulin and albumin in serum. The free fraction of T[sub 4]S in four normal sera averaged 0.06% compared to a value of 0.03% for T[sub 4] (P < 0.001). The serum concentration of T[sub 4]S was (mean [+-] SE) 19 [+-] 1.2 pmol/L in normal subjects, 33 [+-] 10 in hyperthyroid patients with Graves disease, 42 [+-] 15 in hypothyroid patients, 34 [+-] 6.9 in patients with systematic nonthyroidal illnesses, 21 [+-] 4.3 in pregnant women at 15-40 weeks gestation, and 245 [+-] 26 in cord blood sera of newborns; the value in the newborn was significantly different from normal (P < 0.001). Administration of sodium ipodate (Oragrafin; 3 g, orally) to hyperthyroid patients was associated with a transient increase in serum T[sub 4]S. The T[sub 4]S content of the thyroid gland was less than 1/4000th that of T[sub 4]. We conclude that (1) T[sub 4]S is a normal component of human serum, and its levels are markedly increased in newborn serum and amniotic fluid; and (2) the sulfation pathway plays an important role in the metabolism of T[sub 4] in man. 28 refs., 4 figs., 2 tabs.
- OSTI ID:
- 6569636
- Journal Information:
- Journal of Clinical Endocrinology and Metabolism; (United States), Vol. 76:1; ISSN 0021-972X
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
BLOOD
QUANTITATIVE CHEMICAL ANALYSIS
THYROXINE
RADIOIMMUNOASSAY
HYPERTHYROIDISM
SULFATES
AMINO ACIDS
BIOASSAY
BIOLOGICAL MATERIALS
BODY FLUIDS
CARBOXYLIC ACIDS
CHEMICAL ANALYSIS
DIAGNOSTIC TECHNIQUES
DISEASES
ENDOCRINE DISEASES
HORMONES
IMMUNOASSAY
IMMUNOLOGY
ISOTOPE APPLICATIONS
MATERIALS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC IODINE COMPOUNDS
OXYGEN COMPOUNDS
PEPTIDE HORMONES
PROTEINS
RADIOASSAY
RADIOIMMUNODETECTION
RADIOIMMUNOLOGY
SULFUR COMPOUNDS
THYROID HORMONES
TRACER TECHNIQUES
550601* - Medicine- Unsealed Radionuclides in Diagnostics