Submit a comment
Citation Information: J Clin Invest. 1970;49(10):1912-1921. https://doi.org/10.1172/JCI106410.
Abstract
A new method is described for the detection of variations in the release rate of all iodinated products by the thyroid gland in man. 125I was employed to endogenously label the thyroid gland, and a parenterally administered 131I thyroxine dose was used to generate a 131I reference source. Thyroidal iodine release activity was quantitatively assessed by the measurement of variations in 125I/131I ratio values obtained in timed urine samples. Diurnal variation in thyroid release patterns was observed in euthyroid subjects which was promptly suppressed by exogenous triiodothyronine administration and was simulated by the intramuscular injection of 0.25-0.50 U of bovine thyrotropin. The zenith value occurred at 4:00 a.m. ±3.4 hr (SD) and the nadir at 5:00 p.m. ±3.6 hr. The absence of a diurnal pattern in patients with thyrotoxicosis and in secondary hypothyroidism indicated that this diurnal fluctuation was under thyrotropin (TSH) regulation. This new method also promises to be a useful tool for the study of the intrathyroidal recycling of iodide from the iodotyrosine pool and the detection of factors which may acutely alter thyroid function.
Authors
John T. Nicoloff
Guidelines
The Editorial Board will only consider comments that are deemed relevant and of interest to readers. The Journal will not post data that have not been subjected to peer review; or a comment that is essentially a reiteration of another comment.
- Comments appear on the Journal’s website and are linked from the original article’s web page.
- Authors are notified by email if their comments are posted.
- The Journal reserves the right to edit comments for length and clarity.
- No appeals will be considered.
- Comments are not indexed in PubMed.
Specific requirements
- Maximum length, 400 words
- Entered as plain text or HTML
- Author’s name and email address, to be posted with the comment
- Declaration of all potential conflicts of interest (even if these are not ultimately posted); see the Journal’s conflict-of-interest policy
- Comments may not include figures
Copyright © 2025 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)