Evaluation of epididymis storage temperature and cryopreservation conditions for improved mitochondrial membrane potential, membrane integrity, sperm motility and in vitro fertilization in bovine epididymal sperm

Abstract

The maintaining of the epididymis at lower temperatures during storage and transport improves sperm quality. Our study aimed to test whether epididymis storage temperature (post-mortem) and sperm cryopreservation affect sperm kinetics, membrane integrity, mitochondrial potential and fertility capacity. Thirty-six epididymides were collected from 18 bulls after slaughter and divided into two groups: at 4 or 34°C for 2-3 hr. The sperm was collected from the epididymis cauda. The evaluation consisted of computer-assisted sperm analysis (CASA), SYBR14/PI/JC1 to evaluate membrane integrity, mitochondrial membrane potential (MMP) and measurement of lipid peroxidation (TBARS). The sperm was then frozen using an automatic device. After thawing, sperm samples were evaluated by the same variables and further in vitro fertilization rates. Cryopreservation negatively affected sperm motility in samples stored at 4 and 34°C. Nevertheless, the 4°C samples yielded higher rates of blastocyst formation. Pre-freeze sperm motility, progressive motility and velocity were higher in sperm from epididymis stored at 4°C while post-thaw sperm motility, progressive motility and velocity remained the same among samples from epididymis stored at 4 or 34°C. However, with regard to the kinetic patterns, samples collected from epididymis stored at 34°C had lower values when compared to those stored at 4°C prior the cryopreservation process. Our results indicate that epididymis handling conditions after cryopreservation may affect sperm quality after thawing, especially due to compromised MMP in sperm collected from epididymis stored at higher temperatures.

The Stimulated Glycolytic Pathway Is Able to Maintain ATP Levels and Kinetic Patterns of Bovine Epididymal Sperm Subjected to Mitochondrial Uncoupling

“…Epididymal sperm samples were collected and then dissecting the epididymis cauda with a scalpel blade, according to previous protocol [13]. To limit blood contamination, dissection was performed carefully.…”

Morphological description of the male genital organs ofPontoporia blainvillei(Gervais & d’Orbigny, 1844)

“…On the lateral side of each testicle, the presence of epididymis were observed, such as, the presence of head, body and tail, observed previously in cetaceans [15, 25, 26] and in domestic mammals [27, 28]. Moreover, epididymis of P. blainvillei are characterized to be fixed in testis, as in Phocoena phocoena [22].…”

Imidazole and Benzimidazole Modified Half-Sandwich IridiumIIIN-Heterocyclic Carbene Complexes: Synthesis, Anticancer Application, and Organelle Targeting

“…The mitochondria are the main energy-producing sites in cells and play an essential role in apoptosis. Once the mitochondrial membrane is damaged, releases signals, and the damage leads to mitochondrial dysfunction and then induces apoptosis (Nichi et al, 2016). The degree of mitochondrial dysfunction can be evaluated by measuring the changes in mitochondrial membrane potential (MMP; Gómez-Sintes et al, 2016).…”