Decondensation and Pronucleus Formation of Human Spermatozoa Using Different Concentrations of PVP

Hwang, S S; Lee, E Y; Ahn, K H; Sohn, C; Yoon, B K; Lee, J H; Choi, D S

Abstract

In intracytoplasmic sperm injection (ICSI) procedure, polyvinylpyrrolidone (PVP) has been used for easier sperm immobilization and handling. Although it was suspected that PVP could stabilize sperm plasma membrane and possibly interfere with sperm nucleus decondensation, the possible toxicity and appropriate concentrations of PVP for ICSI procedure were not fully elucidated. This study was conducted in order to evaluate the possible harmful effects of high concentrations of PVP on the decondensation and pronucleus (PN) formation. By using fresh and frozen-thawed human spermatozoa, ICSI procedures were performed. The results were as follows. With fresh spermatozoa, the PN formation rates at 2.5%, 5% and 10% of PVP concentration were 52.4%, 55.6% and 60.5%; decondensation rates were 31.0%, 24.2% and 20.9%; and intact sperm head rates were 16.7%, 20.0% and 16.3%, respectively. Using frozen-thawed spermatozoa, the PN formation rates were 50.0%, 47.1% and 50.9%; decondensation rates were 26.9%, 27.5% and 29.1%; and intact sperm head rates were 21.2%, 25.5% and 20.0%, respectively. There were no significant differences among any of the groups (p>0.05). In conclusion, these results indicate that PVP concentrations ranged 2.5% to 10% have little effect on the stabilization of sperm plasma membrane and the sperm nucleus decondensation.