A Contribution to the Biochemistry and Biology of Seminal Plasma

Abstract

When mammalian spermatozoa migrate from the caput to the cauda epididymis, besides other changes, the electrical charge of their membranes is increased (Bedford, 1963). Concomitantly these spermatozoa mature gradually on their way so that caudal spermatozoa become capable of fertilization, in different species to a different extent (Salisbury and Van Demark, 1961; Bedford, 1966). Nevertheless, there are still functional differences between these and ejaculated spermatozoa. In rabbits, for example, fertilization by epididymal spermatozoa, as compared with ejaculated ones, is delayed, and embryo mortality in this case is clearly higher (Orgebin-Crist, 1968). It was assumed that these functional differences might depend on an action of seminal plasma on the spermatozoa during and after ejaculation. It is in this context, that we should like to make the following contribution.