Rapid analysis for iodotyrosines and iodothyronines in thyroglobulin by reversed-phase liquid chromatography.
We describe a 10-min reversed-phase "high-pressure' liquid-chromatographic procedure for measuring tyrosine, monoiodotyrosine, diiodotyrosine, 3,5-diiodothyronine, 3,5,3'-triiodothyronine, 3,3',5'-triiodothyronine, and thyroxine. Resolution and quantitation of a mixture of these amino acids were excellent on LiChrosorb (Altex) RP-8 with isocratic elution (1.5 mL/min) with acetonitrile/water/glacial acetic acid (50/49/1 by vol). As little as 100 ng of each iodoamino acid could be detected and quantitated with a conventional 1-cm, flow-through spectrophotometric (254-nm) detector coupled to a 10-mV strip-chart recorder. Analyses for monoiodotyrosine, diiodotyrosine, 3,5,3'-triiodothyronine, and thyroxine in hog and beef thyroglobulin hydrolysates (sequential digestion with pronase and aminopeptidase) agreed well with results by anion-exchange chromatography and by competitive radioassays. To prevent interference by tryptophan in the analysis for diiodotyrosine, we batch-separated the iodoamino acids by anion-exchange chromatography before the procedure. The procedure we describe seems generally useful for detection and quantitation of thyroid hormones, thyroid hormone metabolites, and iodotyrosines.
D000818:Animals; D002417:Cattle; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D002852:Chromatography, Ion Exchange / Q000379:methods; D004104:Diiodothyronines / Q000032:analysis; D007470:Monoiodotyrosine / Q000032:analysis*; D011869:Radioligand Assay; D013045:Species Specificity; D013552:Swine; D013954:Thyroglobulin / Q000032:analysis*; D013970:Thyronines / Q000032:analysis*; D013974:Thyroxine / Q000032:analysis*; D014284:Triiodothyronine / Q000032:analysis
D004104:Diiodothyronines; D013970:Thyronines; D014284:Triiodothyronine; D013954:Thyroglobulin; D007470:Monoiodotyrosine; D013974:Thyroxine