Thyroxine chromatography

This method was used, for example, for the solid-phase immunoassay of thyroxine (affinity chromatography). Various activation methods (CDI, periodate, and cyanogen bromide procedures) were compared with each other for coupling antibodies to magnetizable cellulose/iron oxide solid-phase particles. 211]... 

Fig. 6. Comparison of immunoassays using clonotype antibodies. The EDso values (thyroxine concentration corresponding to 50% of bound form at zero concentration of thyroxine) in thyroxine immunoassays using clonotype antithyroxine antibody prepared by fast protein liquid chromatography (FPLC). RIA, double-antibody radioimmunoassay FLA, fluorescence polarization immunoassay EIA, enzyme immunoassay. [Cited from Miyai et al. (M5).]...

Also during the sample workup, a certain discrimination may occur. One should avoid situations in which the label is situated in a position that affects solvation properties, pKa values, or derivatization kinetics (Millard, 1978b). Differences in the peak ratio of thyroxine and its 2H2-labeled IS, before and after ion exchange chromatography, however, were ascribed to interfering material originating from the column or solvents (Moller et al., 1983). 

Hay I, Annesley T, Jiang N> Gorman C. Simultaneous determination of d- and L-thyroxine in human serum by liquid chromatography with electrochemical detection, J Chromatogr 1981 226 383-90. 

Peterson B, Hanson R, Giese R, Karger B. Picogram analysis of free triiodothyronine and free thyroxine in serum by equilibrium dialysis and electron capture gas chromatography. J Chromatogr 1976 126 ... 

Snyder SM, Cavalieri RR, Ingbar SH. Simultaneous measurement of percentage free thyroxine and triiodothyronine Comparison of equilibrium dialysis and Sephadex chromatography. J Nucl Med 1976 17 660-4. 

Gika, H., Lammerhofer, M., Papadoyan-nis, I., Lindner,W. Direct separation and quantitative analysis of thyroxine and triiodothyronine enantiomers in pharmaceuticals by high-performance liquid chromatography, J. Chromatogr. B, 2004, 800, 193-201. 

Using bis (trimethylsilyl) acetamide (BSA), volatile trimethylsilyl (TMS) derivatives of the active components 3,5,3, 5 -tetraiodothyronine (thyroxin, TJ and 3,5,3 -triiodothyronine (T3) have been prepared as well as TMS derivatives of the nonphysiologically active components 3,3, 5 -triiodothyronine (T3 ), 3,5-diiodothyronine (T2), and 3,5-diiodo-tyrosine (DIT). Separation and quantitative estimation of these iodinated amino acids is achieved by gas-liquid chromatography. The method is... 

The coupling of two molecules of diiodotyrosine to give one molecule of thyroxine leads to the over-all loss of one alanine side chain, but the form in which this 3-carbon residue is removed is still not yet determined. Up till now, no work has been done on this reaction in the thyroid itself or in isolated thyroid tissues. All the evidence comes from in vitro incubations of diiodotyrosine or its derivatives modelled on von Mutzenbecher s experiments. Johnson and Tewkesbury (1942) found that after such incubations pyruvic acid and ammonia could be detected in the reaction mixture Ohno (see Roche and Michel, 1951) with the aid of chromatography was able to detect serine. Both of these compounds are likely results of the reaction, but at present neither of them has been confirmed. Experiments are still in progress (Pitt-Rivers, unpubhshed) to determine the nature of the alanine residue obtained during aerobic incuba tion of diiodotyrosine or its derivatives. It must, however, be emphasized that even if the nature of this residue were established in in vitro experiments, it would still be necessary to demonstrate that the same reaction takes place in the thyroid gland itself. 

Type of reaction uncatalyzed chemiluminescence "TS, 3,3, 5-triiodo-L-thyronine T4, 3,3 5,5 -tetraiodo-L-thyronine (i-Thyroxine) CAR, continuous-addition-of-reagent technique LC, liquid chromatography. 

Loun, B. Hage, D.S. Characterization of thyroxine-albumin binding using high-performance affinity chromatography. I. Interactions at the warfarin and indole sites of albumin. J. Chromatogr. 1992, 579, 225-235. 

G. Lovell and P.H. Corran, Determination of L-thyroxine in reference serum preparations as the o-phthalaldehyde-V-acetylcysteine derivative by reversed-phase liquid chromatography with electrochemical detection, J. Chromatogr., 1990, 525, 287-296. 

Berger and co-workers [205] have shown that the mixture of mono-and diiodotyrosine, labelled with and thyroxine, can be separated also on Dowex 1x2 (OH ) layers they proposed chromatography on discontinuous layers. 

Measurement of Triiodothyronine and Thyroxine in Human Serum by Gas-Liquid Chromatography Anal. Biochem. 43(2) 433-445 (1971) CA 75 126385w... 

Picogram Analysis of Free Triiodothyronine and Free Thyroxine Hormones in Serum by Equilibrium Dialysis and Electron Capture Gas Chromatography... 

Tetrabromobisphenol A (4,4 -isopropylidenebis(2,6-dibromophenol) TBBPA) is the most widely used BFR in terms of production quantities [2]. It is used as both a reactive and an additive BFR in a variety of polymers, epoxy resins, and adhesives and, in particular, is a constituent in printed circuit boards at levels up to 34% (mass fraction). The acute toxicity of TBBPA is relatively low however, concern for its potential as an endocrine disrupter exists. TBBPA shares structural similarities to thyroxine (T4), and the compoimd competitively binds to the thyroid hormone transport protein transthyretin [135]. Analysis by gas chromatography requires derivitization, and LC methods are preferred to reduce sample processing. Biotransformation of TBBPA... 

Column methods. Thyroxine can be isolated by ion-exchange column chromatography and its iodine content determined as described for PBI. 

Fig. 10. Formation of 3,5,3 -triiodothyronine and of thyroxine by the action of I + on 3,5-diiodotyrosine, followed by radioactivity measurements on the products of the reaction separated by paper chromatography (44). Solvent, iso-pentanol saturated with 6 N NH OH. Abscissa, number of labeled I atoms reacting with one molecule of 3,5-diiodothyronine ordinate, number of labeled I atoms fixed by 3,5-diiodothyronine as tri- or tetrasubstituted derivatives.

My opinion is that the amount of T4 and T3 that can be found in human milk is extremely low. In a newborn drinking for instance half a liter of milk per day, this would only provide about 1 ig of thyroxine, which is obviously of very little help for a hypothyroid newborn. We have no information about rat milk. I should also mention that our original studies, which were performed by measuring T4 and T3 in milk by RIA after several purification steps of the milk to reduce the interference due to the extremely high amounts of fat in the milk, were confirmed later on using gas chromatography. 

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