RESUMEN
The aim of this study was to compare the percentage of sperm tail membrane swelling under hypoosmotic conditions with those with and without pentoxifylline supplements in sperm prepared by the two-layer Percoll gradient method. Twenty five normal semen samples were collected from male partners of infertile couples attending the Infretility Clinic at Siriraj Hospital. After the process of sperm preparation by the two-layer Percoll gradient method, the final samples were divided into 2 tubes, 0.5 ml was added into one tube and another tube was kept as control. The hypoosmotic swelling test was performed on both specimens. The percentage of swollen spermatozoa in the pentoxifylline supplement group was significantly higher than the control group (82.8 + 7.7 vs 70.8 + 12.7; p < 0.00). It was concluded that the addition of pentoxifylline to the sperm prepared by the two- layer Percoll gradient method can enhance the sperm membrane integrity, and it may be beneficial to add pentoxifylline to sperm preparation for use in IUI or IVF.