Determination of active, non-zymogen acrosin, proacrosin and total acrosin in different andrological patients.

A spectrophotometric assay is described which, due to improved extraction conditions, allows quantitative determination of enzymatically active, non-zymogen acrosin, proacrosin and total acrosin activity from human sperm acrosomes. Acrosomal proteinase activity is assessed by acid extraction of the sperm pellet and the suspension medium before and after snap-freezing, followed by zymogen autoactivation. Release of acrosin from the acrosome can be used as a sensitive biochemical marker to characterize acrosomal membrane stability, severe disturbance of which may be the cause of impaired male fertility. Acrosin activities in different populations of semen specimens are reported and compared to data available in the literature. Different degrees of acrosomal membrane alterations are observed in men with oligozoospermia, tetratozoospermia and polyzoospermia. Particularly in oligozoospermia, a significant increase of active, non-zymogen acrosin points to severe acrosomal membrane alterations and, in addition, to a premature activation of proacrosin, which may impair fertilization in certain individuals. Finally, acrosin activity is shown to be significantly influenced by the time of sexual abstinence. It is concluded that determination of acrosin may be a useful indicator of the fertility potential in men.