The effects of melatonin supplement on paddlefish (Polyodon spathula) sperm quality and ATP content in sperm during in vitro storage

Melatonin (MLT) is a well-known antioxidant and can improve sperm quality during storage in many species. In the present study, the effects of different concentration of MLT (0.1, 0.5, 1 and 5 μM) on paddlefish sperm quality and ATP content in sperm were evaluated during semen storage at 4 °C. Compared with other groups, 0.5 μM MLT supplement in semen could be more effective to improve the plasma membrane integrity, maintain the steady reactive oxygen species (ROS) level and inhibit decrease of mitochondrial membrane potential of the non-activated sperm during whole storage. To the activated sperm, the total motility, progressive motility, beat cross frequency of sperm in semen with 0.5 μM MLT was significant higher (p