Polyamines protect boar sperm from oxidative stress in vitro

Area of Science:

• Reproductive Biology
• Biochemistry
• Cell Biology

Background:

• Sperm are vulnerable to damage from excessive reactive oxygen species (ROS).
• Polyamines like spermine and spermidine, abundant in seminal plasma, possess potent antioxidant properties.
• Understanding polyamine uptake and their protective mechanisms in sperm is crucial for improving semen preservation.

Purpose of the Study:

• To investigate the uptake of spermine and spermidine by boar sperm.
• To determine if polyamines protect boar sperm against ROS-induced oxidative stress.
• To evaluate the efficacy of polyamine supplementation in boar semen preservation.

Main Methods:

• Analysis of polyamine content in boar seminal plasma under different storage conditions.
• Fluorescent labeling of spermine and spermidine to study their uptake, inhibited by organic cation transporter (OCT) inhibitors.
• In vitro experiments assessing sperm motility, plasma membrane and acrosome integrity, ROS levels, antioxidant enzyme activities, and oxidative stress markers in supplemented semen.

Main Results:

• Polyamines spermine and spermidine are present in boar seminal plasma and their levels decrease during storage.
• Sperm uptake of spermine and spermidine is mediated by organic cation transporters (OCTs).
• Supplementation with spermine and spermidine significantly improved sperm motility, plasma membrane and acrosome integrity, reduced ROS levels, enhanced antioxidant capacity, and mitigated oxidative damage markers under both storage and oxidative stress conditions.

Conclusions:

• Spermine and spermidine are effectively taken up by boar sperm and play a vital role in protecting against oxidative stress.
• Polyamines exert their protective effects through direct antioxidant activity and by modulating key antioxidant enzymes.
• Supplementation of boar semen extenders with spermine and spermidine enhances semen preservation quality and efficacy.