J Tesarik1, C Mendoza, A Carreras. 1. Institut National de la Santé et de la Recherche Médicale (INSERM) U-187, Clamart, France.
Abstract
OBJECTIVE: The hypothesis that defective expression of D-mannose binding sites (presumptive elements of the sperm-zona pellucida binding mechanism) is related to male infertility was tested. DESIGN: Experiments were performed on sperm samples from two groups of men classified, respectively, as fertile and infertile, based on their reproductive history. SETTING: The study was carried out in an andrologic laboratory of a University Hospital. PATIENTS, PARTICIPANTS: Fertile men were healthy sperm donors; infertile men were patients with fertility problems. INTERVENTIONS: D-mannose binding sites were visualized by fluorescence microscopy using a mannosylated neoglycoprotein probe. MAIN OUTCOME MEASURES: The hypothesis as reported in the objective section was formulated before data collection and was not modified thereafter. RESULTS: Sperm from fertile men displayed a characteristic pattern of changes in the expression of D-mannose binding sites during in vitro capacitation. This pattern was altered in sperm from infertile men. CONCLUSIONS: If the relationship between defective expression of D-mannose binding sites and decreased sperm fertilizing ability is validated by parallel tests of sperm-zona binding, it may be used for development of chemical tests replacing the current ones using human zonae pellucidae.
OBJECTIVE: The hypothesis that defective expression of D-mannose binding sites (presumptive elements of the sperm-zona pellucida binding mechanism) is related to male infertility was tested. DESIGN: Experiments were performed on sperm samples from two groups of men classified, respectively, as fertile and infertile, based on their reproductive history. SETTING: The study was carried out in an andrologic laboratory of a University Hospital. PATIENTS, PARTICIPANTS: Fertile men were healthy sperm donors; infertilemen were patients with fertility problems. INTERVENTIONS:D-mannose binding sites were visualized by fluorescence microscopy using a mannosylated neoglycoprotein probe. MAIN OUTCOME MEASURES: The hypothesis as reported in the objective section was formulated before data collection and was not modified thereafter. RESULTS: Sperm from fertile men displayed a characteristic pattern of changes in the expression of D-mannose binding sites during in vitro capacitation. This pattern was altered in sperm from infertilemen. CONCLUSIONS: If the relationship between defective expression of D-mannose binding sites and decreased sperm fertilizing ability is validated by parallel tests of sperm-zona binding, it may be used for development of chemical tests replacing the current ones using human zonae pellucidae.