Seminal Oligouridinosis: Low Uridine Secretion as a Biomarker for Infertility in Spinal Neurotrauma

BACKGROUND: Compromised sexual health is a major rehabilitative barrier for men with lower-spinal cord injury (SCI). Although studies have revealed decreased sperm motility, the quantitative biochemical changes that underlie the infertility mechanism remain poorly understood. METHODS: We employed a nontargeted approach combining 800 MHz hydrogen nuclear magnetic resonance (H-1 NMR) spectroscopy and ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) with pattern recognition methods to analyze seminal fluid metabolite profiles in 10 men with and 8 without SCI above thoracic vertebra 10 (T10). RESULTS: The metabolic phenotype for SCI could be predicted from the H-1 NMR data. The median concentration of uridine in fertile controls was 1.55 mmol/L (range 1.0-5.0 mmol/L), but was undetectable by both NMR and MS in all but 2 individuals from the SCI group, one who later fathered a child without assisted fertility techniques. CONCLUSIONS: We hypothesize that uridine is likely to be an essential precursor to metabolites required for capacitation and is a potential marker for the prognosis of post-SCI functional fertility recovery. We derived the term seminal oligouridinosis to describe this newly identified condition.