The effect of kallikrein on human sperm membrane function.

To illustrate the influence of kallikrein on the hypoosmotic swelling test, 84 human semen samples were classified into 4 groups: normospermia (n = 34, group A), oligospermia (n = 18, group B), asthenospermia (n = 8, group C), and oligoasthenospermia (n = 24, group D). Two aliquots of 0.45 ml were prepared from each specimen in all the groups: one was incubated for 3 hr in a glass tube containing kallikrein and the other was incubated without kallikrein (control). Quantitative and qualitative assessment of sperm motility and the hypoosmotic swelling test (HOST) were subsequently performed in each pair of samples. Percentage of motile spermatozoa, speed of forward progression of motile spermatozoa and the percentage of swollen sperm were significantly lower in the control samples than in samples treated with kallikrein in all the groups. Kallikrein was also proved effective in increasing the outcome of the HOST, the percentage of motile spermatozoa and the speed of forward progression of washed spermatozoa received from normospermic men (n = 15). It seems that kallikrein has a direct effect on sperm membrane and improves its properties and functions.