Comprehensive elucidation of amino acid profile in human follicular fluid and plasma of in vitro fertilization patients

Abstract

The assessment of oocyte quality in human in vitro fertilization (IVF) is in focus of intensive studies. Follicular fluid (FF) constitutes the major medium for the developing oocyte and therefore it is a perfect target to search for the biomarkers of female infertility. The objective of this study was to compare the amino acid (AA) profile of human FF and plasma (PL) (from 96 IVF patients) and to examine if the AA composition is related to oocyte quality, IVF results and women’s infertility. In both biological fluids, Gln, Gly and Ala appeared as dominant AAs. Most of AAs are more abundant in PL; the exceptions are Glu, Thr, Ala and Gly, which are higher in FF and Gln, Arg and Phe, the contents of which are similar in both biological fluids. Ser in FF and Met and Phe in PL were detected as potential biomarkers as their content varied depending on the IVF outcome. Significant differences were also detected between the groups of different infertility reasons. Our results suggest that intra-follicular AAs might reflect the condition of the preovulatory follicle and together with PL, AAs can be used to characterize the infertility etiology and oocyte quality related to IVF outcome.