Effect of glucuronic acid on sperm viability, acrosome reaction, and intracellular reactive oxygen species during liquid storage in pigs

Abstract

Background: The preservation of boar semen is essential for optimizing artificial insemination outcomes and maintaining sperm functionality during liquid storage. Glucuronic acid (GA) is involved in cellular detoxification and homeostasis regulation and may relate to oxidative processes. However, its effect on boar semen preservation remains unclear. This study aimed to investigate the effects of GA addition on sperm viability, acrosome reaction, and intracellular ROS level during liquid storage in pigs. Methods: Boar semen was collected by the gloved-hand method and transported at 17℃. Samples were diluted with extenders containing 0, 0.5, 1.0, 2.5, and 5.0 mM GA and stored at 17℃ for 7 days. Sperm viability, acrosome reaction, and intracellular ROS levels were detected using SYBR-14/PI, FITC-PNA/PI, and DCFDA/PI double staining and analyzed by flow cytometry. Results: Sperm viability was higher in the 0.5 mM GA group than in the 0 mM group at 72 h, with no difference at 120 h and 168 h. Acrosome reaction showed no difference at 72 h and 120 h, but was lower in the 5.0 mM group than in the 0 mM group at 168 h. Intracellular ROS levels were similar among treatments at 72 h and 168 h, but were higher in the 5.0 mM group than in the 0 mM group at 120 h. Conclusions: GA supplementation showed concentration- and storage-dependent effects, with a transient viability increase at 0.5 mM (72 h) and a reduced proportion of acrosome-reacted sperm at 5.0 mM (168 h), while ROS was not decreased and was elevated at 5.0 mM at 120 h, suggesting the need for dose optimization.