Oxalate in human seminal plasma: possible significance and problems of oxalate determination.

Objective: To determine the level of oxalate in seminal plasma and to correlate it with andrologic variables.

Design: Laboratory examination.

Setting: University-based department of andrology and department of clinical chemistry.

Patient(s): One hundred male outpatients with infertility.

Intervention(s): Isolated seminal plasma was stored for 120 days at -20 degrees C.

Main Outcome Measure(s): Levels of oxalic acid in seminal plasma.

Result(s): Oxalate levels in seminal plasma depend on the degradation of ascorbic acid to oxalic acid during storage. There was a linear nonenzymatic increase of oxalate with storage time. After 120 days of storage, the values were 133 +/- 50 micromol/L (n = 100). Oxalic acid correlated significantly with the number of sperm head anomalies, the pH value, and the age of the donors and correlated negatively with the volume of ejaculate.

Conclusion(s): Oxalic acid in seminal plasma may influence male fertility.