Time and Media-Dependent Modulation of Sperm Capacitation in Red-Rumped Agouti (Dasyprocta leporina Linnaeus, 1758)

The increasing focus on understanding spermatozoa mechanisms in rodents aims to enhance reproductive stability and support conservation efforts, particularly for ecologically significant and declining species like the red-rumped agouti. We aimed to evaluate the interaction between capacitation media and time, testing BSA concentrations-low (4 mg/mL) and high (15 mg/mL)-with or without 2 mM calcium chloride (CaCl₂) across three time points. Epididymal sperm were distributed into five groups: without capacitation agent (WCA), high BSA (HBSA), high BSA with CaCl₂ (HBCa), low BSA (LBSA), and low BSA with CaCl₂ (LBCa), each incubated for 1, 3, or 6 h. Total sperm motility was significantly higher only in media with CaCl₂. However, only LBCa maintained high progressive motility. LBCa and HBCa maintained membrane integrity, mitochondrial functionality, and reduced reactive oxygen species levels, but only LBCa increased glutathione levels. HBSA, HBCa, LBSA, and LBCa improved the sperm capacitation rate, but LBCa yielded the highest proportion of capacitated sperm and acrosome-reacted cells after 6 h. Hyperactivation rates were higher in both LBCa and HBCa after 6 h. Therefore, the optimal condition for red-rumped agouti sperm capacitation is a low BSA concentration (4 mg/mL) supplemented with 2 mM calcium chloride following a 6 h incubation.