Determination of 27 amino acids' levels in seminal plasma of asthenospermia and oligospermia patients and diagnostic value analysis

Amino acids (AAs) are abundant in seminal fluid and play an important role in the reproduction process. However, the functional significance of AAs in seminal is not clear. This study was designed to profile the AAs in seminal fluid of asthenozoospermia (AS) and oligospermia (OL) patients and evaluate its potential diagnostic value. To determine the true function of AAs in seminal fluid, an ultra high performance liquid chromatography-mass spectrometry (UPLC-MS/MS) was developed and validated. The seminal fluid samples collected from 76 AS patients, 58 OL patients, and 76 healthy subjects were determined by UPLC-MS/MS and analyzed by fisher discriminant and receiver operating characteristic (ROC). The results showed that, the AAs levels were dramatically decreased in AS and OL patients compared with healthy subjects. What's more there were significant variation in the AAs profile of AS and OL patients. Specifically, some polar AAs decreased, while nonpolar AAs increased in OL patients. Based on the level of AAs, 93.4 % of original and 90.9 % of cross -validated grouped cases were correctly classified between AS patients, OL patients, and healthy subjects. The further ROC analysis shows that glutamic acid, tyrosine, aspartic acid, proline, and tryptophan have the diagnostic value (P < 0.01) in the three groups. Moreover, aspartic acid and glutamic acid exhibit a high correlation (Correlation Coefficient >0.9) in AS, OL, and healthy subjects. In conclusion, there are significant variation in AAs profile in seminal plasma of AS and OL patients with high accuracy in fisher classification. The associations between the levels of AAs in seminal fluid of AS, OL, and healthy subjects may have clinical applications in providing valuable diagnostic indicator. (C) 2020 Published by Elsevier B.V.