Francielli Weber Santos

The aim of the study was to evaluate the efficiency of the gelatin and Hypromellose capsules as recipients to vitrification of lambari spermatogonial cells. In experiment 1, four protocols to vitrification (P1, P2, P3 and P4) were tested. The protocol P3 showed greater cell viability (25.42± 4.19%) compared to the other treatments. In experiment 2, evaluated the gelatine and hypromellose capsules in comparation with the cryotubes as recipients for vitrification. Variables as: concentration and viability cellular, mitochondrial activity, and oxidative stress were analyzed. Cryotubes obtained higher cellular concentration in comparation to the gelatine and hypromellose capsules, while it showed similarity in cellular viability with the gelatine capsule. Mitochondrial activity was not different among the treatments as the lipid peroxidation. Cryotubes and hypromellose capsule obtain highest levels of antioxidant capacity. These results suggest that biodegradables capsules have the capacity to preserved testicular tissue to obtain viable spermatogonial cells after vitrification and warming. In addition to play an important role as an alternative of vitrification recipients.

Oxidative stress plays a key role in the mechanisms underlying pathophysiological processes, such as inflammation, age-related degenerative phenomena, atherosclerosis, hypertension, cancer, diabetes mellitus, neurodegenerative diseases, xenobiotic toxicity, among others. It is generated by the production of free radicals, resulting from the oxidative metabolism of cells. Oxidative stress is an important defense against infections. It acts specifically as a vasodilator and helps modulate antioxidant mechanisms. However, the effects become harmful when its production increases or antioxidant mechanisms are excessively reduced. Toxic metals from environmental and occupational exposure are silent agents that induce oxidative stress. Metals such as mercury (Hg), aluminum (Al), cadmium (Cd), and lead (Pb) are known to be toxic to various organs and tissues in our body. The present mini-review focuses on the cardiovascular system, considering that the interplay between oxidative stress and toxic metals acting silently is involved in their harmful effects, especially on the etiopathogenesis of cardiovascular disorders. A brief review is also given regarding the mechanisms of modulation of redox homeostasis by organic mechanisms, pharmacological approaches that can act directly or indirectly as antioxidants, and food-derived compounds that appear to be effective inhibitors of oxidative stress, thus preventing the harmful effects of free radicals.

Ketosis is a significant metabolic disorder caused by negative energy balance (NEB). β-hydroxybutyrate (BHBA) is the most abundant circulating ketone body and is known to accumulate within follicular fluid. Although NEB and metabolic stress conditions have been associated with reduced fertility in cows, the effect of increased BHBA on the viability and functionality of bovine cumulus-oocyte complexes (COC) is poorly understood. The aim of this study was to determine the effects of BHBA on expansion, oxidative status, and endoplasmic reticulum (ER) stress in cumulus cells, oocyte nuclear maturation, and in vitro embryo production (IVP) in cattle. Cumulus-oocyte complexes were treated with 0, 2, or 4 mM of BHBA for 6, 12, 18, or 24 h during oocyte in vitro maturation (IVM.) Cumulus expansion and mRNA levels of genes related to cumulus expansion, oxidative status, ER stress, and autophagy were evaluated. The oocytes were fixed for nuclear maturation analysis at 24 h of IVM. In addition, after IVM with BHBA for 24 hours, cleavage and blastocyst rates were examined. No difference was observed in the rates of oocytes reaching metaphase II, cleavage, and blastocysts. Furthermore, the oxidative status and relative abundance of mRNA for genes associated with antioxidant enzymes and autophagy were not altered by BHBA in cumulus cells. However, BHBA altered the total area of the COC and increased the mRNA levels of genes associated with ER. In conclusion, BHBA affects the expansion and induces ER stress in bovine cumulus cells during IVM without compromising oocyte nuclear maturation, oxidative status, cleavage, and blastocyst rates.

Objetivou-se avaliar o efeito metafilático do disseleneto de difenila no desempenho, perfil metabólico e status oxidativo de bezerras de corte submetidas ao desmame precoce. Foram utilizadas 30 bezerras taurinas de corte, filhas de vacas primíparas, entre 60 a 110 dias de vida. As bezerras foram distribuídas de forma randomizada em três grupos experimentais. Grupo controle (GC, n=10): 2 mL de solução de NaCl a 0,9%. Grupo dimetilsulfóxido (GDMSO, n=10): 2 mL de dimetilsulfóxido a 99,2%. Grupo disseleneto de difenila (GDD, n=10): 3 µmol/kg de (PhSe)2 a 98%, diluído em 2 mL de dimetilsulfóxido 99,2%. O intervalo entre dias considerado como momentos (M), foi de 14 dias, e a avaliação de peso e coleta de amostras de sangue ocorreu no M1=basal (-28 dias), M2 (-14 dias), M3 (dia 0), M4 (14 dias) e M5 (28 dias), já as administrações dos tratamentos no M1, M2, M3. Houve efeito significativo para momento: ganho médio diário (P<0,0001), proteína total (P<0,0001), globulina (GL) (P<0,0001), glutationa reduzida (P=0,0263), substâncias reativas ao ácido tiobarbitúrio (P<0,0001) e potencial antioxidante redutor férrico (P<0,0001), exceto para albumina (P=0,1374). A suplementação com disseleneto de difenila em bezerras de corte desmamadas precocemente não preveniu a alteração de parâmetros oxidativos sanguíneos, sugerindo a ocorrência de estresse oxidativo. Porém, no grupo tratado com disseleneto de difenila houve incremento no ganho de peso, proteína total e globulina, propondo que o uso deste antioxidante em momentos estratégicos pode sim condicionar os animais, promover bem estar e reduzir os efeitos deletérios causados pelo desmame, como a perda de peso.

The aim of this study was to evaluate the effects of different selenium compounds on the sperm quality of cryopreserved ram semen. Ejaculates from four rams, collected using an artificial vagina heated to 38 °C, were individually evaluated. The approved ejaculates were pooled and diluted (1:1 v:v) in Tris-egg yolk extender (20%, v/v) and separated into two control groups, one cooled for 2 h and the other for 4 h. The pooled ejaculates at the two cooling periods were supplemented with two doses (0.5 and 1 μg/mL) of organic selenium (ORG), and inorganic selenium (SeNa), each. The samples were packed in 0.25 ml straws, at a concentration of 400 × 10⁶ sperms/mL and stored in liquid nitrogen. The straws were thawed in a water bath at 37 °C for 20 s, and the samples were subjected to sperm kinetics evaluation by Computer Assisted Semen Analysis software. Sperm membrane integrity, acrosome morphology, and mitochondrial potential were assessed. In addition, oxidative stress markers reactive oxygen species (ROS), ferric reducing antioxidant power (FRAP), thiobarbituric acid reactive species (TBARS), and glutathione peroxidase (GPx) enzyme activity) were also evaluated. No significant improvement was observed in the ram semen quality at the two cooling times. Supplementation of the freezing extender with 0.5 μg/mL ORG, subjected to 4 h cooling period, increased the sperm motility when compared with the control group at the same cooling time. In addition, the 0.5 μg/mL SeNa group, under the 2 h cooling period, showed an increase in sperm motility when compared to the control group at the same cooling period. Considering the importance of sperm motility as a fertility parameter, our study indicates that supplementation with ORG and SeNa can help improve the total motility of the cryopreserved ram semen.

The aim of this study was to evaluate the effects of diphenyl diselenide (PhSe) supplementation during the transition period on the metabolism, immunity, oxidative status, and milk production of postpartum dairy cows. Twenty-seven Holstein females were divided into groups: (PhSe) (DDG), which received 3 μmol/kg of (PhSe)₂ in 4 mL of dimethyl sulfoxide (DMSO) subcutaneously, DMSO (DMSOG), and NaCl (NACLG) which received 4 mL of DMSO and 0.9% NaCl. Evaluation of body condition score (BCS), weighing and administrations were performed at 42, 28, and 14 days prepartum, and on the day of calving (0). On days 0, 7, 14, 21, and 35 postpartum, BCS was evaluated, and blood were collected. Colostrum was obtained from the first postpartum milking. Production was measured, and milk was collected on days 7, 14, 21, and 35 postpartum. DDG showed higher values of total protein (TP) and globulins (GLOB) 7 days postpartum and increase from day 0 to days 21 and 35. DDG immunoglobulin G (IgG) was higher on days 21 and 35, and increased between days 7 and 21. In postpartum TP, GLOB and IgG are physiologically reduced, therefore, the results indicate that supplementation of transition females with (PhSe) stimulated postpartum humoral immunity.