Preliminary study on metabolites of polyunsaturated fatty acids in seminal plasma of Guizhou Province population

Abstract

Objective To investigate the differences in polyunsaturated fatty acid metabolites in seminal plasma between normal group and low sperm motility group, and their relationship with sperm motility. Methods Totally 581 human seminal plasmas collected from Guizhou Province were divided into normal group and low sperm motility group according to the motility rate. The metabolite products of 24 kinds of polyunsaturated fatty acids were detected by liquid phase tandem mass spectrometry/mass spectrometry (LC-MS/MS). Through the in vitro culture experiment of sperm, the culture supernatant was collected during the culture of the upstream screening sperm for 24 h, and the polyunsaturated fatty acid products with different differences detected in the different groups of seminal plasma were also verified by LC-MS/MS method. Results Among the polyunsaturated fatty acid metabolites detected in seminal plasma, the concentrations of 9-hydroxyoctadecadienoic acid (9-HODE) and 13-hydroxyoctadecadienoic acid (13-HODE) in the seminal plasma of the low sperm motility group were significantly different from those in the normal seminal plasma group (P=0.001, P=0.033). In vitro culture experiments showed that the concentration of 9-HODE and 13-HODE in the culture medium increased significantly with the prolongation of culture time and the decrease of sperm motility rate (P=0.003, P=0.035). Statistical analysis showed that the concentrations of 9-HODE and 13-HODE were significantly negatively correlated with sperm motility （r=-0.91，P=0.045；r=-0.95，P=0.026）. Considering the sperm density factor in the analysis of polyunsaturated fatty acid metabolites and sperm motility in the seminal plasma of the population, the results showed that 9-HODE and 13-HODE were significantly higher in the low sperm motility group than in the normal group (P<0.000 1). And there was a negative correlation (r=-0.38) with the sperm motility rate (P<0.000 1). Conclusion 9-HODE and 13-HODE are released into the culture medium and seminal plasma by sperm cell metabolism, which is a potential indicator of the degree of sperm membrane damage, which may be helpful in judging and detecting the asthenospermia. Key words: Sperm; Polyunsaturated fatty acid; Tandem mass spectrometry