Quantification by magnetic resonance spectroscopy of metabolites in seminal plasma able to differentiate different forms of azoospermia

The aim was to determine whether proton magnetic resonance spectroscopy(1H-MRS) of metabolites such as glycerophosphorylcholine (GPC), choline,citrate and lactate in human seminal plasma can be used to differentiate(i) different azoospermic patients and (ii) different forms ofspermatogenic failure including those who had undergone radiation therapyor chemotherapy. Semen samples were provided by men with obstructiveazoospermia and spermatogenic failure who had serum follicle stimulatinghormone (FSH) values within the normal range and either more or less thannormal. Four prominent constituents of seminal plasma were identified by1H-MRS: GPC, choline, citrate and lactate. The peak area ratios ofcholine/citrate as well as choline/lactate were significantly different (P< 0.01) between groups with spermatogenic failure and obstructiveazoospermia. When the serum FSH values were normal in men withspermatogenic failure and obstructive azoospermia, a significant differencewas found in the GPC/choline ratio (P < 0.001). When the FSH values werenormal, the GPC/choline ratio appeared to be a very important parameterable to differentiate not only between cases of spermatogenic failure andobstructive azoospermia but also between different forms of spermatogenicfailure. These results demonstrate the potential use of 1H-MRS on humanseminal plasma in a new approach in the management of male infertility.