[Effects of seminal plasma on the survival and fertility of spermatozoa kept in vitro].

In sperm cell populations kept in vitro, the profiles of motile cell number and motility are always influenced by the seminal plasma. The non-epididymal fraction of the seminal plasma first enhanced and then depressed bull, ram and goat sperm motility or immediately depressed that of horses and rabbits. The secretions of Cowper's gland (male goat) or of the seminal vesicles (boar) were implicated in the depressive effect of the non-epididymal plasma fraction on the maintenance of sperm motility. These secretions were responsible for variations in motility correlated with variations in sperm fertility. The level and significance of these correlations indicated that the seminal plasma might be involved in sperm fertility, perhaps owing to a type A lecithinase secreted by Cowper's gland (bull, ram and male goat) or by a protein of vesicular origin (boar).