LIMITATIONS OF THE CHICK RADIOPHOSPHORUS UPTAKE ASSAY AND THE CHICK RADIOIODINE DEPLETION ASSAY FOR THYROTROPIC HORMONE WHEN APPLIED TO BLOOD AND URINE12

Publisher Website
Google Scholar
Abstract
The chick thyroid P32 uptake and I131 depletion methods for the bioassay of anterior pituitary thyrotropic hormone (TSH) have been applied to the measurement of TSH in human serum and urine. Although there are detectable levels of TSH in sera from some patients with myxedema, hypcrthyroidism, or exophthalmos, the levels in normal individuals arc too low to measure accurately. The ultrafiltrate residue of urine contains a non-hypophyseal factor which stimulates the uptake of P32 by the chick thyroid, which imposes limitations on the application of the P32 uptake assay to urine. Urine ultrafiltrate residue also contains a non-hypophyseal factor which interferes with the effect of TSH on I131 depiction in the chick thyroid. Assay of TSH in human serum or urine by these methods will require, therefore, either concentration of TSH from serum or elimination of interfering factors from urine.