Male fertility and protein C inhibitor/plasminogen activator inhibitor-3 (PCI): localization of PCI in mouse testis and failure of single plasminogen activator knockout to restore spermatogenesis in PCI-deficient mice.

Objective: To investigate the mechanisms responsible for the testicular abnormalities and infertility of previously generated male protein C inhibitor (PCI)-deficient mice.

Design: Determination of the localization of PCI in the reproductive organs of wild-type males. Generation of double knockout mice lacking the protease inhibitor PCI and one plasminogen activator, either urokinase (uPA) or tissue plasminogen activator (tPA), both of which are PCI-target proteases.

Setting: Animal research and histologic analysis.

Animal(s): Male mice of desired genotype.

Intervention(s): Fertility testing of double knockout mice.

Main Outcome Measure(s): Infertility of PCI(-/-)uPA(-/-) and PCI(-/-)tPA(-/-) double knockout mice.

Result(s): In the testes of wild-type males PCI was detected in spermatocytes of prophase I, as well as in late spermatids and mature spermatozoa, but absent from somatic cells. All PCI(-/-) uPA(-/-) and PCI(-/-) tPA(-/-) male mice were infertile and histologic analysis of testis showed similar alterations as previously described for PCI(-/-) mice.

Conclusion(s): The abnormal spermatogenesis of PCI (plasminogen activator inhibitor-3)-deficient mice cannot be rescued by single plasminogen activator knockout.