Absence of Fas protein detection by flow cytometry in human spermatozoa

Objective: To investigate the expression of Fas protein on the surface of ejaculated spermatozoa of normozoospermic and nonnormozoospermic men. Design: Prospective study. Setting: University infertility clinic. Patient(s): Twenty-three volunteer normozoospermic men (controls) and 4:3 men undergoing infertility evaluation (cases). Intervention (s): Analysis of ejaculated spermatozoa by indirect immunofluorescence of Fas protein by flow cytometry. Main Outcome Measure(s): Comparison of flow cytometric analysis of autofluorescence, control tests (secondary antibody and isotype control), and experimental tests (anti-Fas monoclonal antibody) in the spermatozoa of ejaculated samples. Result(s): No expression of Fas protein was found on the surface of ejaculated spermatozoa of controls and cases. Conclusion(s): The Fas molecules are not present in substantial amounts in the ejaculated spermatozoa of normozoospermic and nonnormozoospermic men. Therefore, our results do not support the "abortive apoptosis" theory. (C) 2004 by American Society for Reproductive Medicine.