The pharmacological actions of lipid extracts from human seminal fluid were first discovered by von Euler in 1935 . The effective substances were called prostaglandins, since the site of their production was presumed to be in the prostate. The concentrations of PGE2, PGEi and their 19-hydroxy-derivatives in seminal fluid are higher than in all other body fluids. For this reason they were isolated for the first time in pure form from this source . 19-Hydroxy-PGE has not been found in
Figure 8-11. Hypothetical model of a cytokine-prostaglandin network at the chorio-decidual interface that is involved in the pathophysiology of infection-induced pre-term labor (from Mitchell et al. ; reproduced with permission of W. B. Saunders Co.).
other tissues. Later it was recognized that the biosynthesis of PGE mainly takes place in seminal vesicles, where particular high activities of prostaglandin endoperoxide PGE-isomerase (9-keto-prostaglandin-isomerase) are present  and that the contribution of the prostate to prostaglandin production is low. Prostaglandins are not enzymatically inactivated in seminal fluid. In spite of these early findings the biological functions of eicosanoids in the male reproductive tract have still not been fully evaluated. Possible actions include effects on sperm function, maturation and capacitation, mediation of ejaculation and induction of immune tolerance towards paternal antigen within the female reproductive tract.
Was this article helpful?