Effects of kinins and dipeptidyl carboxypeptidase on the motility of highly washed human sperm.
The influences of bradykinin, kallidin and dipeptidyl carboxypeptidase (kininase II) on the motility of human sperm thoroughly washed with Ficoll were investigated by an objective method with multiple exposure photography technique which recorded stroboscopically the tract of sperm migration. Addition of 0.1--10 ng/ml of bradykinin or kallidin to sperm suspension caused a stimulation of motility. The effect appeared by increase of the velocity of forward motile sperm, whereas the percent of motile sperm was not altered. On the contrary, higher dose of kinins suppressed the motility by decreasing the percent of motile sperm. There was a minor contamination of dipeptidyl carboxypeptidase even in the highly washed sperm suspension. This enzyme was identical with angiotensin I converting enzyme or kininase II and the major enzyme of kinin degrading activity in seminal plasma. Stimulation of sperm motility by kinin was further enhanced in the presence of SQ 14225, a specific inhibitor of dipeptidyl carboxypeptidase, by protection of added kinins from the residual dipeptidyl carboxypeptidase in the sperm suspension. Dipeptidyl carboxypeptidase level in ejaculated human semen was found to correlate to the semen quality, such as sperm density and motility, but it gave no direct influence on sperm motility.
D001920:Bradykinin / Q000494:pharmacology; D010450:Endopeptidases / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D007609:Kallidin / Q000494:pharmacology; D007705:Kinins / Q000494:pharmacology*; D008297:Male; D013081:Sperm Motility / Q000187:drug effects*; D013997:Time Factors
D007705:Kinins; D007609:Kallidin; D010450:Endopeptidases; C020071:dipeptidyl carboxypeptidase; D001920:Bradykinin