ASSESSMENT OF THE TRYPSIN-LIKE HUMAN PROSTATIC KALLIKREIN, ALSO KNOWNAS HK2, IN THE SEMINAL PLASMA OF INFERTILE MEN - RESPECTIVE CONTRIBUTIONS OF AN ELISA PROCEDURE AND OF WESTERN BLOTTING

Human seminal plasma (SP) is a unique source of kallikreins, Prostate- specific antigen (hK3), which is a chymotrypsin-like human prostatic k allikrein (CHPK), and its cousin protein (hK2), which is recognized as a trypsin-like human prostatic kallikrein (THPK), have been assessed in infertility disorders to test the hypothesis that oligoasthenoterat ozoospermia (OAT) is associated with an abnormal prostatic function. M onoclonal antibodies specific for THPK (hK2) were produced by Immunova , Canada, and used to develop a new enzyme-linked immunosorbent assay procedure and to perform Western blot analyses in SP. The immunoradiom etric assay from Hybritech Inc., San Diego, Calif., was selected for C HPK (hK3) measurements in SP. Determinations of the THPK and of CHPK c ontents in SP from four groups of subjects were performed after valida tion of the assays. The concentration of both kallikreins was similar in three groups of infertile men, and no statistical difference from t he control group was recorded. Western blot analysis confirmed the exi stence of different molecular forms of both kallikreins in SP, General ly, these molecular forms were not affected by infertility disorders e xcept when obstructive azoospermia led to the exclusion of seminal ves icles, which are the sources of protein C inhibitor (PCI), No THPK-PCI complex was observed because THPK, unlike CHPK, is bound mainly to PC I within a few minutes after ejaculation. These data suggest that meas urements of kallikreins in the SP of infertile men are much less usefu l than evaluation of their different molecular forms. Specifically, th e absence of THPK-PCI appears to be a reliable feature of obstructive azoospermia, and this test should be routinely practiced in andrology laboratories.