Sulfate conjugates of iodothyronines in developing sheep: effect of fetal hypothyroidism
Autor: | A. Reviczky, Sing-Yung Wu, D. Polk, Wen-Shen Huang, Delbert A. Fisher, K. Wang |
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Rok vydání: | 1993 |
Předmět: |
medicine.medical_specialty
Triiodothyronine Reverse Physiology Endocrinology Diabetes and Metabolism Biology chemistry.chemical_compound Fetus Sulfation Hypothyroidism Physiology (medical) Internal medicine Thyronines medicine Animals Sulfate Sheep Triiodothyronine Sulfates Thyroid Embryogenesis Metabolism Body Fluids Fetal Diseases Thyroxine medicine.anatomical_structure Endocrinology chemistry embryonic structures Thyroidectomy Hormone |
Zdroj: | American Journal of Physiology-Endocrinology and Metabolism. 265:E115-E120 |
ISSN: | 1522-1555 0193-1849 |
DOI: | 10.1152/ajpendo.1993.265.1.e115 |
Popis: | We recently showed that thyroxine sulfate (T4S) and 3,3',5-triiodothyronine sulfate (T3S) were major thyroid hormone metabolites in ovine fetuses and neonates. To further characterize the sulfation pathway in ovine fetuses, we measured 3,3',5'-triiodothyronine (rT3S) in serum and other body fluids in samples obtained from fetal (n = 23, 94-145 days of gestational age, term = 150 days), newborn (n = 6), and adult (n = 6) sheep. In addition, T3S, T4S, and rT3S levels were measured in tissue fluids and serum samples obtained from ovine fetuses 13 days after total thyroidectomy (Tx) conducted at gestational age of 110-113 days (n = 5). Sham-operated twin fetuses served as controls (n = 5). The relative order of mean rT3S concentration for various tissue fluids in fetuses were meconium > bile > serum > allantoic fluid > urine or amniotic fluid. Peak mean tissue fluid levels generally occurred at 110-130 days gestation. In hypothyroid fetuses, significant decreases in the mean serum concentrations of T4S and rT3S, but not T3S, were noted. The mean rT3S level also was decreased significantly in allantoic fluid, bile, and meconium, whereas T4S and T3S levels were reduced only in bile of the Tx fetuses. These data demonstrate that sulfation is a major pathway in thyroid hormone metabolism in both euthyroid and hypothyroid ovine fetuses. |
Databáze: | OpenAIRE |
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