[Phospholipase A in the semen. Occurrence, properties and possible physiological significance]

Phospholipase A2 activities have been detected in seminal plasmas of different vertebrates. These enzyme activities significantly correlate with the prostanoid contents. Considering these findings and the general regulatory function of phospholipase A2 in prostanoid biosynthesis, it is concluded that the seminal phospholipase A2 functions in triggering biosynthesis of seminal prostanoids, both being released predominantly by the vesicular and/or prostate glands. Phospholipase A2, which has been purified to homogeneity from human seminal plasma as the obviously richest enzyme source, clearly resembles pancreatic phospholipase A2 in many of its properties. In principle stimulatory as well as inhibitory effects of various drugs on fertility seem to be possible via alterations in the biosynthesis of seminal prostanoids as a consequence of drug effects on phospholipase A2 activities.