Action of swim-up and caffeine on equine frozen sperm

Abstract

Cryopreservation of equine semen is crucial to semen commercialization. However, it reduces sperm motility and longevity. Thus, sperm selection methods and addition of motility-activating substances to sperm, such as caffeine, may improve sperm quality of equine frozen semen. The objective of the current work was to evaluate the effects of caffeine on recovery and quality parameters of frozen-thawed sperm subjected to swim-up selection to be used in intracytoplasmic sperm injection (ICSI) in assisted reproductive techniques. Stallion semen were frozen and after thawing different caffeine concentrations were added to the samples performing four treatments control (no caffeine), 3, 5, and 7.5 mM caffeine. Sperm kinematic and motility were assessed by computer-assisted sperm analysis (CASA). Then, the four treated samples were submitted to the swim-up sperm selection, and the number of recovered sperm and morphology were evaluated at four times 20, 40, 60, and 80 min. The swim-up increased the recovery proportion of normal morphology sperm without (80.1±1%) or with caffeine addition (3mM: 81.2±1%, 5mM: 79.9±1% and 7.5 mM 78.9±1%) compared to the thawed semen (70±2%). However, the addition of 5 mM caffeine induced an increase in sperm motility (38.9±2.8 vs. 32.6±3.4%, P<0.05), and sperm recovery after swim-up (7.9x10 6 vs. 3.4x10 6 sperm/ml, P<0.05) compared to the control. The addition of 5 mM caffeine to frozen-thawed equine semen before swim-up selection improved sperm motility and increased the sperm recovery rate while not decreasing the percentage of morphologically normal sperm. Thus, caffeine addition to frozen-thawed equine semen before swim-up selection has potential clinical application in improving sperm quality for use in ICSI.

Strategies for Bacterial Eradication from Human and Animal Semen Samples: Current Options and Future Alternatives

“…The upper supernatant is sterilely collected [ 42 ]. Several modifications of swim-up technique were also reported for humans [ 88 , 89 , 90 , 91 ] and animal species [ 92 , 93 , 94 ]. Chen et al [ 95 ] reported that 57.4% of semen samples processed by swim-up were bacteria-free, and only 23.8% were retrieved in the case of density gradient centrifugation.…”

Quality and fertilizing ability of frozen–thawed porcine sperm separated using a migration sedimentation method

“…Caffeine activates sperm motility by inhibiting phosphodiesterase, thereby improving sperm motility and longevity (Alves et al., 2022). Caffeine increases the half‐life of cAMP by converting it to its acyclic form and activating protein kinases (Huo et al., 2002), thereby stimulating motility, cyclic hyperactivation, capacitation, and acrosome reactions (Mbizvo et al., 1993).…”