Analysis of the Relationship Between Defective Sperm Function and the Generation of Reactive Oxygen Species in Cases of Oligozoospermia

TLDR

The study investigates the relationship between sperm‑oocyte fusion in response to A23187 and reactive oxygen species production in human sperm. This relationship was examined by measuring sperm‑oocyte fusion after A23187 stimulation alongside ROS generation. Fertile men showed high fusion and low ROS, whereas most oligozoospermic patients had poor fusion, with some exhibiting low ROS and impaired seminal liquefaction and others showing high ROS, indicating a biochemical defect that may inform etiology and treatment.

Abstract

The ability of human spermatozoa to exhibit sperm‐oocyte fusion in response to the ionophore, A23187, was examined in relation to the capacity of these cells to generate reactive oxygen species. In 70 fertile control donors, there was an overwhelming pattern of high levels of sperm‐oocyte fusion associated with low levels of reactive oxygen species production. By contrast, 88% of the 74 oligozoospermic patients exhibited < 25% oocyte penetration in response to A23187 and 58% exhibited no penetration whatsoever. Of the 40 oligozoospermic patients who failed to respond to A23187, nine had low levels of reactive oxygen species production in association with impaired liquefaction of seminal plasma. Of the remainder, 17 (55%) exhibited defective sperm function together with elevated production of reactive oxygen species. These observations, which are the first to describe a biochemical defect in the spermatozoa of oligozoospermic patients, may carry significant implications for the etiology and treatment of this condition.