SEPARATION OF HUMAN SPERMATOZOA WITH HYALURONIC-ACID INDUCES, AND PERCOLL(R) INHIBITS, THE ACROSOME REACTION

The effect on the acrosome reaction of human spermatozoa of two widely used sperm separation media, hyaluronic acid (Sperm Select(R)) and Pe rcoll(R), was studied. Viable and highly motile fractions of human spe rmatozoa were separated from seminal plasma using self-migration on a Percoll(R) gradient. After translocation of separated spermatozoa from the Percoll(R) solution to a culture medium, serum, Percoll(R) or hya luronic acid (Sperm Select(R)) was added to aliquots of the spermatozo a containing culture medium. At increasing time intervals, the influx of Ca-45(2+) into spermatozoa was measured and the concentration of vi able spermatozoa that had undergone the acrosome reaction was analysed using the triple stain technique. Serum was found to be necessary to support sperm motility and viability. Compared to culture medium with serum only, addition of hyaluronic acid induced influx of Ca-45(2+) an d the acrosome reaction, whilst Percoll(R) inhibited both of these act ions. Hyaluronic acid (Sperm Select(R)) added to spermatozoa separated by a 'swim-up' method induced, and the addition of Percoll(R) inhibit ed, influx of Ca-45(2+) when compared to the addition of culture mediu m with serum only. This study demonstrates that both hyaluronic acid ( Sperm Select(R)) and Percoll(R) affect the acrosome reaction and the p rerequisite for Ca2+ influx in human spermatozoa. These effects should be taken into consideration when using these media for preparation of spermatozoa for insemination or for fertilization in vitro.