2Dmitry Rogachev Federal Scientific Clinical Center of Pediatric Hematology, Oncology, and Immunology, Ministry of Health of the Russian Federation, ul. Samora Mashel 1, 117198 Moscow, Russia; fax: +7 (495) 664-7090
3All-Russian Research Institute of Metrological Service, ul. Ozernaya 46, 119361 Moscow, Russia; fax: +7 (495) 437-5666; E-mail: email@example.com
* To whom correspondence should be addressed.
Received November 10, 2014; Revision received December 8, 2014
Previous studies showed that large amounts of phenylcarboxylic acids (PhCAs) are accumulated in a septic patient’s blood due to increased endogenous and microbial phenylalanine and tyrosine biotransformation. Frequently, biochemical aromatic amino acid transformation into PhCAs is considered functionally insignificant for people without monogenetic hereditary diseases. The blood of healthy people contains the same PhCAs that are typical for septic patients as shown in this paper. The overall serum PhCAs level was 6 µM on average as measured by gas chromatography with flame ionization detection. This level is a stable biochemical parameter indicating the normal metabolism of aromatic amino acids. The concentrations of PhCAs in the metabolic profile of healthy people are distributed as follows: phenylacetic ≈ p-hydroxyphenyllactic > p-hydroxyphenylacetic > phenyllactic ≈ phenylpropionic > benzoic. We conclude that maintaining of stable PhCAs level in the serum is provided as the result of integration of human endogenous metabolic pathways and microbiota.
KEY WORDS: tyrosine metabolism, sepsis, phenylcarboxylic acids, phenyllactic acid, p-hydroxyphenyllactic acid, phenylpropionic acid, benzoic acid, microbiota