Human oviductal cells produce a factor(s) that maintains the motility of human spermatozoa in vitro.

OBJECTIVE: To characterize in part the factor(s) in conditioned medium (CM) that maintains sperm motility after human oviductal cell culture.

DESIGN: Controlled, experimental, laboratory study.

SETTING: University-based gynecology unit.

PATIENT(S): Fallopian tubes were obtained from patients who underwent tubal ligation or hysterectomy. Semen with normal sperm parameters was obtained from men who visited subfertility clinics.

INTERVENTION(S): Spermatozoa were incubated with CM and their motility was evaluated by a computer-aided sperm analysis system.

MAIN OUTCOME MEASURE(S): Curvilinear velocity, straight-line velocity, average path velocity, linearity, amplitude of lateral head displacement, beat cross-frequency, and percentage of spermatozoa that exhibited hyperactivation.

RESULT(S): Compared with their baseline motility (0 hour), spermatozoa incubated with CM maintained various motility parameters for a longer period than did control spermatozoa. All the motility parameters of the CM-treated spermatozoa were higher than those of the control spermatozoa at the same time point. This effect of CM was dose-dependent and increased with the duration of incubation. The effect was stable at 56 degrees C but was not observed after 100 degrees C heat treatment. Trypsin, but not proteinase K, abolished the effect. A fraction with a molecular weight of <3 kd in the CM was responsible for the observed effect.

CONCLUSION(S): Human oviductal cells produce a peptide(s) that maintains sperm motility.