Separation of human semen on Percoll gradients: effect on percentage of motile and morphologically normal sperm and proportion of acrosome reacted sperm.

Abstract

Objectives: To examine whether sperm motility and morphology correlate with ability to undergo the acrosome reaction in vitro.

Methods: Sixty-one seminal specimens were separated on a discontinuous Percoll gradient (70%, 40%). Percentages of motile and morphologically normal sperm, their motility grade, and percentages of acrosome-reacted sperm before and following acrosome reaction inducing treatment were estimated.

Results: Percentage of motile sperm from normozoospermic specimens increased from whole semen (47.6 +/- 5.6) to sediments (59.6 +/- 13.0). Motility grade exhibited a similar trend (2.1 +/- 0.5 and 3.6 +/- 0.5-scale of 1-4). Percentage of morphologically normal sperm increased from semen (27.3 +/- 10.9) to sediment (53.8 +/- 14.8). All differences were statistically significant, (P < 0.00). In abnormal semen the motility grade and percentage of morphologically normal sperm also increased from semen to sediment (1.9 +/- 0.4 to 3.2 +/- 0.8 and 17.7 +/- 7.8 to 37.1 +/- 15.4 respectively, (P < 0.001). Percentages of motile sperm were similar. In normozoospermic sediments, both non-treated or treated to induce the acrosome reaction, proportions of acrosome-reacted sperm were significantly higher than in semen (18.3 +/- 6.9% and 20.0 +/- 6.5% vs. 6.8 +/- 4.2% respectively, P < 0.001). A similar trend was obtained using abnormal aliquots; however, the acrosome-reacted sperm accounted for only 9.0 +/- 5.1% and 10.8 +/- 4.3% versus 5.4 +/- 2.8% (P < 0.025).

Conclusions: Morphology and motility of sperm were correlated with the proportion of acrosome-reacted sperm.