Abstract
Whether the motility and velocity of washed human spermatozoa can be affected by different compounds usually found in seminal plasma was examined. The following purified substances were added to washed spermatozoa in physiological concentrations: bradykinin, angiotensin, I, II, III, spermine, spermidine, acetylcarnitine, LH [luteinizing hormone] and FSH. Sperm motility and velocity were measured by the method of multiple exposure photography after 30 min of incubation at 22.degree. C and 37.degree. C including appropriate controls. Bradykinin improved sperm velocity at 22.degree. C. Angiotensin I and II, acetylcarnitine and LH stimulated sperm velocity at 37.degree. C. The latter 2 substances increased also sperm motility at 37.degree. C. Angiotensin III, spermine, spermidine and FSH showed no effect on sperm motility neither at 22.degree. C nor at 37.degree. C. Apparently, distinct physiological compounds found in seminal plasma stimulate directly sperm motility and/or velocity in vitro and support the assumption that the sperm motility stimulating principle of human semen is complex and of multifactorial origin.