Ultrastructure of human spermatozoa in the presence of the spermicide nonoxinol-9 and a vaginal contraceptive containing nonoxinol-9.

The effect of nonoxinol-9, a potent non-ionic, surface-active spermicide and of the vaginal contraceptive Patentex oval containing this spermicide, on human sperm ultrastructure were studied by transmission electron microscopy. Pooled human semen was mixed either with nonoxinol-9 to give a final concentration of 1.25 or 0.05% or with Patentex oval (final concentration of the spermicide nonoxinol-9 1.25%). Saline containing no spermicidal agent served as control. After incubation at 37 degrees C for 10 min., the washed sperm pellet was processed for electron microscopy. Human spermatozoa from control experiments showed a normal ultrastructure whereas significant changes occurred after the addition of nonoxinol-9 or Patentex oval to human semen. The plasma membrane and the acrosomal membrane complex were removed. The nuclear membrane was swollen, showed breaks, discontinuities and an enlarged submembranous space. Different stages of nuclear chromatin decondensation were observed. In the middle piece, the bi-laminar membrane of the mitochondria appeared as a mono-layer membrane. The normal cristae were destroyed, the mitochondriae were empty or contained fine granular material. The observed irreversible severe membrane alterations cause an immediate devitalization of the spermatozoa and support the effectiveness of the spermicide nonoxinol-9 and the vaginal contraceptive Patentex oval.