KINEMATIC RESPONSE OF HUMAN SPERMATOZOA TO NONOXYNOL-9

This study was an examination of the dose response of the kinematics o f human sperm motion to 1-min and 30-min incubations with the spermici de Nonoxynol-9 (N9). At concentrations resulting in only slight reduct ions in percentages of motile sperm (MOT), increasing N9 decreased the progressiveness of sperm motion (reflected in decreasing straightline velocity). This decline in progressiveness resulted from both decline in the vigor (reflected in decreasing curvilinear velocity; VCL) and disruption of the pattern (reflected in decreasing linearity; LIN) of such motion. Since, after the 1-min incubation, VCL declined only slig htly for seminal sperm over this range of N9 concentrations, declines in sperm progressiveness were primarily due to decreases in LIN. For s perm collected from the pellet fraction from a Percoll gradient techni que, however, VCL declined substantially even at low concentrations of spermicide. These Percoll-separated sperm were, on the other hand, le ss sensitive to N9 than seminal sperm in terms of the dose response of MOT. This added resistance may be attributed to selection or to envir onmental or physiological changes caused by Percoll separation. Respon ses in mean amplitude of lateral head displacement (ALH) to increasing N9 also differed for the two treatments, increasing on average for se minal sperm while decreasing on average for Percoll-separated sperm.