Analysis of spermatozoa from the proximal vas deferens of fertile men

Fluids from the left and right proximal vas deferens were collected from 105 normal fertile men by cannulating the vas deferens during vasectomy, and sperm parameters analysed. Sperm motility (73.1 +/- 13.3%), normal sperm morphology (75.2 +/- 11.1%), sperm viability (72.7 +/- 18.8%) and the hypo-osmotic swelling test (73.3 +/- 19.2%) were in the normal range, compared with that of ejaculated spermatozoa. However, sperm concentration in the proximal vas deferens (6274.6 +/- 5103.8 x 10(6) ml-1 was higher than that in semen. Sperm concentration in the right vas deferens was significantly higher (P < 0.05) than that in the left and the percentage of spermatozoa showing abnormal cervical mucus penetration was significantly higher (47%) for the left than for the right (18%). There were no anti-sperm antibodies on the surface of spermatozoa from the vas deferens as determined by the sperm cervical mucus contact test and immunobead test. These parameters of spermatozoa from the proximal vas may reflect those of spermatozoa from the human cauda epididymis.