Sperm interaction with fallopian tube apical membrane enhances sperm motility and delays capacitation

Abstract

Objective: To understand the effect of sperm contact with the apical plasma membrane of tubal epithelial cells on sperm motility, velocity, and capacitation. Design: Prospective, controlled in vitro study. Setting: University medical center. Patient(s): Women of reproductive age undergoing hysterectomy for benign gynecologic indications and normozoospermic donors of proved fertility. Main Outcome Measure(s): Sperm motility as measured manually, velocity as measured by computer-assisted sperm motility analysis, and capacitation status as measured by the chlortetracycline fluorescence assay. Result(s): Sperm incubated with apical membrane vesicles had a significantly higher motility at 12 (87.4% ± 3.4% versus 69.2% ± 4.8% [mean ± SEMI), 24 (85.2% ± 3.1% versus 60.5% ± 7.2%) and 48 hours (78.9% ± 5.3% versus 42.4% ± 11.3%) compared with control (sperm incubated with human tubal fluid media in the absence of apical membrane vesicles) (n = 4). Progressive velocity was significantly higher at 12 (78.2 ± 1.4 versus 61.7 ± 16.1μm/s) and 24 (66.2 ± 3.9) versus 34.4 ± 9.8μm/s) hours (n = 4). Incubation with apical membrane vesicles significantly slowed the transition from uncapacitated to capacitated chlortetracycline fluorescence pattern (n = 5). Conclusion(s): Contact with the apical plasma membrane of tubal epithelial cells enhances sperm motility and delays sperm capacitation in vitro.