title: Radioimmunoassay of 3,3',-'-triiodo-L-thyronine (reverse T3) in human serum and its application in different thyroid states.
abstract: A radioimmunoassay for the measurement of 3.3',5'-triiodo-L-thyromine (reverse T3, rT3) has been developed. The known limitations of this technique have been overcome by the use of the biologically relevant L-compound for the production of highly specific antisera and for preparing the standard curve. The high sensitivity of the assay (lower limit of detection 20 ng/l serum) was obtained by using 125I-labelled rT3 of maximum specific radioactivity. Mean serum rT3 concentrations for various thyroid states were as follows: Normal subjects: 0.182 mug/l (0,280 nmol/l), hypothyroidism: 0.038 mug/l (0.058 nmol/l), hyperthyroidism: 0.522 mug/l (0.802 nmol/l), pregnants: 0.200 mug/l (0.307 nmol/l), newborn (cord serum): 2.11 mug/l (3.24 nmol/l). The method described should provide additional information with regard to the clarification of thyroxine metabolism.
mesh_terms: D003429:Cross Reactions; D005260:Female; D005312:Fetal Blood / Q000032:analysis; D006801:Humans; D006980:Hyperthyroidism / Q000097:blood; D007037:Hypothyroidism / Q000097:blood; D007231:Infant, Newborn; D007700:Kinetics; D011247:Pregnancy; D011863:Radioimmunoassay / Q000379:methods; D013959:Thyroid Diseases / Q000097:blood*; D014284:Triiodothyronine / Q000097:blood*
chemical_list: D014284:Triiodothyronine