Abstract
Kallikrein, a kinin-releasing proteinase, significantly stimulates human sperm motility in fresh ejaculates with primarely reduced sperm motility (asthenozoospermia) as well as in 24 hours stored ejaculates with reduced sperm motility resulting from post-ejaculatory aging processes. adiition of a kininogen source (serum) further significantly improved sperm motility of kallikrein-stimulated ejaculates. In contrast to the 24 hours lasting stimulation of kallikrein, enhancement of sperm motility by kinins is limited to 2 hours after addition of a single dose of kallidin (1 ng/ml).