Thyroidal Radioiodine Uptake Rate Measurement in Infants

Journal Article · Fri Jun 01 04:00:00 EDT 1962 · Archives of Pediatrics & Adolescent Medicine

DOI:https://doi.org/10.1001/archpedi.1962.02080020755002· OSTI ID:4690674

FISHER, D. A.

In neonatal term and premature infants measurements were made of thyroidal I¹³¹ clearance rate and 24-hr I¹³¹ uptake. Iodide space and renal iodide excretion were measured to allow calculation of k₁, the fraction of the iodide space cleared per minute by the thyroid. Mean iodide space was 0.432 plus or minus 0.072 1/kg. Mean protein-bound iodine at a mean age of 25 hr in term infants was 9.1 plus or minus 1.4 mu g%. During the first 2 days in term infants the mean K₁ value was 2.37 x 10^-3 per minute and mean 24-hr uptake 62%. In premature infants within the first 3 days, mean K₁ was 3.37 x 10 ^-3 per minute and mean 24-hr uptake 72%. Mean k₁ in 21 premature infants between 5 and 55 days was 0.58 x 10^-3 per minute and mean 24-hr uptake 17%. The elevated I¹³¹ uptake values seen neonatally were manifest by 10 hr of age and maximal within the first 48 hr. Values returned to normal by 5 days of age. Neonatal thyroid function, characterized by an early, marked elevation of serum hormonal iodine with an associated relative saturation of thyroxine-binding protein, appears to be secondary to an increased thyroid-stimulating hormone (TSH) effect manifest by an early increase in thyroid I¹³¹ uptake rate. Possible etiology of the neonatal TSH stimulation is discussed in terms of TSH stimulation secondary to the neonatal fail in temperature and/or a stress response.

• Research Organization: Univ. of Arkansas, Little Rock
• Sponsoring Organization: USDOE
• NSA Number: NSA-17-027020
• OSTI ID: 4690674
• Journal Information: Archives of Pediatrics & Adolescent Medicine, Journal Name: Archives of Pediatrics & Adolescent Medicine Journal Issue: 6 Vol. 103; ISSN 1072-4710
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
AGE
HORMONES
IODINE 131
MAN
MATHEMATICS
METABOLISM
QUANTITY RATIO
THYROID