Improvement in Membrane Integrity and Acrosin Levels of Human Sperm by Use of L4 Membrane

Abstract

Previous results have demonstrated the advantage of using an L4 filter as a method for sperm preparation in assisted reproductive techniques. The present study examined the effect of two sperm processing methods (L4 filter and swim-up) on sperm acrosin levels and the integrity of the sperm membrane as measured by the hypoosmotic swelling (HOS) test. Semen specimens from 35 men (19 suspected subfertile men and 16 normal volunteers) were used to measure acrosin activity; 30 specimens (14 patients and 16 normal men) were used to assess the integrity of sperm membrane by the HOS test. The acrosin activity of L4-filtered spermatozoa (mean 110 ± 85 μIU acrosin/10⁶ sperm) in patients and donors was significantly higher (p <. 002) than in either the swim-up specimens (76 ± 58 μIU) or original unprocessed ejaculate (46 ± 27 μIU). Similarly, the percentage of tail swelling measured by HOS test was significantly higher (p <. 01) in the L4- filtered sperm (mean 71 ± 13%) than in either swim-up specimens (59 ± 18%) or original ejaculate (61 ± 10%). These results clearly demonstrate improvement in two important functional parameters of sperm fertilizing ability in sperm processed by the L4-filter technique, thereby providing new evidence in support of the use of L4 filters for sperm processing.

Key Words:

• spermatozoa
• L4 membrane
• acrosin
• hypoosmotic swelling test
• semen
• swim-up