OBJECTIVETo investigate the effects of the metabolite produced by Trichomonas vaginalis on human sperm motility in vitro.

METHODSTrichomonas vaginalis having been cultured, the culture solution containing metabolite was obtained by removing the protozoa, then diluted into 3 kinds of concentration. Sperm was obtained from 10 healthy fertile men by masturbation and prepared by swim-up technique to produce a spermatozoon solution of high motility. Every sperm sample was divided into 4 groups (A, B, C, D). Unused culture solution was added to Group A as control, and the other 3 groups (B, C, D) were respectively incubated with the above used culture solution at 3 kinds of concentration (1.2 x 10(9)/L, 6 x 10(8)/L, 1.2 x 10(8)/L). Measurements were carried out at 30 s, 1 h, 2 h, 4 h, 6 h by CASA.

RESULTSSperm motility decreased in both Group B and C markedly, and the effects displayed a concentration- and time-dependent manner.

CONCLUSIONThe metabolite of Trichomonas vaginalis can reduce human sperm motility in vitro, and may be one of the causes of infertility.