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

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 +/- SEM]), 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 +/- 16.1 microns/s) and 24 (66.2 +/- 3.9 versus 34.4 +/- 9.8 microns/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.