Glycerophosphocholine in seminal plasma of fertile and infertile men.

Glycerophosphocholine (GPC) was measured in seminal plasma from 65 fertile men, 276 infertile men and 10 men before and after vasectomy, using a new enzymatic method. Extra-epididymal excretion of GPC accounted for 30% of the total seminal levels of GPC. From a diagnostic point of view, GPC determination did not appear to be a specific tool which could discriminate between secretory and excretory azoospermia. Although the seminal content of GPC was related positively to the total sperm count in both fertile and infertile men, there was an inverse relationship between the level of GPC and sperm motility when considering classes displaying the same total sperm count. This was observed in all classes from infertile men as well as in fertile men with a total sperm count lower than 200 x 10(6) sperm/ejaculate. These results suggest a possible role of GPC in the regulation of human sperm motility, which warrants further investigation.