IN-VITRO KALLIKREIN TREATMENT OF HUMAN SPERMATOZOA - STIMULATION OF SPERM PENETRATION INTO ZONA-FREE HAMSTER EGGS DEPENDS ON THE QUALITY OFINITIAL SEMEN PARAMETERS BUT NOT ON CONSTITUENTS OF THE KALLIKREIN-KININ SYSTEM IN SEMINAL PLASMA

We investigated the effect of an in vitro kallikrein treatment of huma n spermatozoa on their ability to penetrate zona-free hamster eggs. Si xty-four infertility patients were classified into four groups (normo- , oligo-, astheno-, and oligoasthenozoospermia) in order to find out w hich men would benefit most from this procedure. An aliquot of each ej aculate was diluted with Ham's F-10 medium supplemented with human ser um albumin and kept at 22C for 1 hour. Another aliquot was incubated w ith kallikrein (5 KU/ml.) for one hour at 22C. These sperm suspensions were then washed twice, subjected to a swim-up preparation, and subse quently incubated at 37C for 2 hours. The mean penetration rates of ka llikrein-treated samples were significantly higher than those of the c orresponding control assays in all but the oligoasthenozoospermia grou p. Our results suggest a direct proteolytic action of kallikrein becau se the stimulation of penetration into hamster eggs was not correlated with the amount of constituents of the kallikrein-kinin system (kinin s, kininogen, kininase) in seminal plasma.