title: Radioimmunoassay for 3,3',5'-triiodothyronine (reverse T3, R-T3) in unextracted human serum.
abstract: Highly specific antibodies against 3,3',5'-triiodothyronine (reverse T3, R-T3) have been produced in rabbits. The crossreaction with T4 is about 0.05%. A radioimmunoassay for R-T3 in unextracted serum was developed. ANS is used for blocking the binding of tracer and endogenous R-T3 to TBG. The sensitivity to the assay is 0.06 ng/ml plasma. The mean normal R-T3 concentration is 0.20 ng/ml. Thyrotoxic patients show elevated levels; in most hypothyroid patients R-T3 concentrations are below the detection limit.
mesh_terms: D000906:Antibodies; D003429:Cross Reactions; D006801:Humans; D006980:Hyperthyroidism / Q000097:blood; D007037:Hypothyroidism / Q000097:blood; D007536:Isomerism; D007700:Kinetics; D011863:Radioimmunoassay / Q000379:methods; D013974:Thyroxine / Q000097:blood; D014284:Triiodothyronine / Q000097:blood* / Q000276:immunology
chemical_list: D000906:Antibodies; D014284:Triiodothyronine; D013974:Thyroxine