Article ID Journal Published Year Pages File Type
1200382 Journal of Chromatography A 2012 9 Pages PDF
Abstract

3-Iodothyronamine (T1AM) is an endogenous derivative of thyroxine. Recently there have been numerous reports of analytical methods to quantify endogenous T1AM levels, but substantial discrepancies in concentration depending on the method of analysis (LC–MS/MS or immunoassay) suggest endogenous T1AM may be covalently modified in vivo. Using information dependent acquisition methods to perform unbiased scans for T1AM metabolites following a single IP injection in mice, we have identified O-sulfonate-T1AM, N-acetyl-T1AM and T1AM-glucuronide as conjugates occurring in vivo, as well as the oxidatively deaminated 3-iodothyroacetic acid and non-iodinated thyroacetic acid. 3-iodothyroacetic acid, O-sulfonate-T1AM and T1AM-glucuronide are present in serum at greater concentrations that unmodified T1AM and all metabolites are extensively distributed to tissues. These results suggest covalent modifications of T1AM may play a critical role in regulating distribution and biological activity of T1AM, and analytical methods to quantify endogenous T1AM should be able to account for these metabolites as well.

► T1AM metabolites were identified using information dependent acquisition methods. ► T1AM is extensively metabolized in mouse serum following a single IP injection. ► MRM LC–MS/MS methods were validated to quantify T1AM metabolites in serum. ► T1AM-glucuronide and Ac-T1AM were identified as novel compounds.

Related Topics
Physical Sciences and Engineering Chemistry Analytical Chemistry
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