Even getting FT4 nd FT3 tested is often extremely difficult or costly. Now these researchers are claiming to be able to measure 11 thyroid hormones and their metabolites in a ridiculously small blood sample. I mean, how big is a tadpole? You don't get a vacutainer-full of blood from them.
Maybe we have to come back as frogs to get properly tested?
It would be interesting to know how much this sort of testing might cost?
Also, I wonder what they would find out by doing this sort of test throughout the day in humans? Would we see incredibly complex patterns - or a fairly simple picture?
Paper in Forefront
Analytical and Bioanalytical Chemistry
First online: 23 May 2016
Quantification of 11 thyroid hormones and associated metabolites in blood using isotope-dilution liquid chromatography tandem mass spectrometry
Martin Hansen , Xuan Luong, David L. Sedlak, Caren C. Helbing, Tyrone Hayes
This paper describes a novel analytical methodology for the simultaneous determination of absolute and total concentrations of 11 native thyroid hormones and associated metabolites, viz. thyroxine (T4), 3,3′, 5-triiodothyronine (T3), 3,3′, 5′-triiodothyronine (rT3), 3,5-diiodothyronine (3,5-T2), 3,3′- diiodothyronine (3,3′-T2), 3-iodothyronine (T1), thyronine (T0), 3-iodothyronamine (T1AM), tetraiodothyroacetic acid (Tetrac), triiodothyroacetic acid (Triac), and diiodothyroacetic acid (Diac), in 50-μL of plasma or serum. The method was optimized using four isotopic labeled surrogate and internal standards in combination with solid-phase extraction and LC-MS/MS. The methodology was further evaluated using amphibian plasma and serum with matrix-matched calibration applied for quantification. Method detection limits are 3.5 pg T4, 1.5 pg T3, 2.9 pg rT3, 1.7 pg 3,3′–T2, 2.3 pg 3,5-T2, and between 0.3 and 7.5 pg for the remaining six metabolites in 50 μL aliquots of blood sera or plasma. Accuracies and repeatabilities for all analytes were between 88 and 103 % and 1.31 and 17.2 %, respectively. Finally, we applied the method on adult frog (Xenopus laevis) plasma and tadpole (Rana (Lithobates) catesbeiana) serum. We observed up to seven different thyroid hormones and associated metabolites in tadpole serum. This method will enable researchers to improve the assessment of thyroid homeostasis and endocrine disruption in animals and humans.