Pregnancy and Luteal Responses to Embryo Reinsertion following Embryo Flushing in Donor Mares.

The effect of embryo reinsertion immediately after embryo flushing was studied. In Experiment 1, eight mares were used during 32 cycles (8 cycles in each group). For the first two groups, inseminated mares were flushed 8 days after ovulation and prostaglandin F2α was not administered: in group EF-ET (embryo flushing and embryo transfer) the embryo was reinserted in the same donor mare, while in the EF group, no further procedure was performed.

Effects of repeated embryo flushing without PGF administration on luteal function, percentage of unwanted pregnancy and subsequent fertility in mares.

Background: PGF is commonly given at the end of embryo flushing (EF) to shorten the interval to the next oestrus and ovulation.

Objectives: To determine the effect of repeated EF on plasma progesterone concentration, percentage of mares with endometritis, unwanted pregnancy and subsequent fertility in mares flushed without the use of PGF.

Study Design: Controlled experiments.

The effect of dexamethasone and flunixin-meglumine on ovulation, endometrial oedema, and inter-ovulatory interval length in the mare.

The use of flunixin-meglumine (a potent non-steroidal anti-inflammatory drug) during the critical period of intrafollicular prostaglandin production before ovulation (24 and 36 h after hCG treatment) results in a high rate of ovulatory failure and formation of haemorrhagic anovulatory follicles (HAF) in the mare. Dexamethasone is commonly used to prevent persistent mating-induced endometritis in susceptible mares, but the effect on ovulation blockage within the pre-ovulatory critical window of intrafollicular prostaglandins production following hCG administration has not been determined. Six mares were followed during four consecutive cycles in a crossover design; once in oestrus with a follicle of >32 mm in diameter, mares were treated with hCG (Hour 0) and assigned to one of 4 groups randomly: 1) FM, mares received 1.

Vaginal Microbiota Is Stable throughout the Estrous Cycle in Arabian Maress.

Lactic acid bacteria (LAB) dominate human vaginal microbiota and inhibit pathogen proliferation. In other mammals, LAB do not dominate vaginal microbiota, however shifts of dominant microorganisms occur during ovarian cycle. The study objectives were to characterize equine vaginal microbiota in mares by culture-dependent and independent methods and to describe its variation in estrus and diestrus.

Ebselen impairs cellular oxidative state and induces endoplasmic reticulum stress and activation of crucial mitogen-activated protein kinases in pancreatic tumour AR42J cells.

Ebselen (2-phenyl-1,2-benzisoselenazol-3(2H)-one) is an organoselenium radical scavenger compound, which has strong antioxidant and anti-inflammatory effects. However, evidence suggests that this compound could exert deleterious actions on cell physiology. In this study, we have analyzed the effect of ebselen on rat pancreatic AR42J cells.

Depletion of Intracellular Thiols and Increased Production of 4-Hydroxynonenal that Occur During Cryopreservation of Stallion Spermatozoa Lead to Caspase Activation, Loss of Motility, and Cell Death.

Oxidative stress has been linked to sperm death and the accelerated senescence of cryopreserved spermatozoa. However, the molecular mechanisms behind this phenomenon remain poorly understood. Reactive oxygen species (ROS) are considered relevant signaling molecules for sperm function, only becoming detrimental when ROS homeostasis is lost.

Inhibition of Mitochondrial Complex I Leads to Decreased Motility and Membrane Integrity Related to Increased Hydrogen Peroxide and Reduced ATP Production, while the Inhibition of Glycolysis Has Less Impact on Sperm Motility.

Mitochondria have been proposed as the major source of reactive oxygen species in somatic cells and human spermatozoa. However, no data regarding the role of mitochondrial ROS production in stallion spermatozoa are available. To shed light on the role of the mitochondrial electron transport chain in the origin of oxidative stress in stallion spermatozoa, specific inhibitors of complex I (rotenone) and III (antimycin-A) were used.

Phosphorylated AKT preserves stallion sperm viability and motility by inhibiting caspases 3 and 7.

AKT, also referred to as protein kinase B (PKB or RAC), plays a critical role in controlling cell survival and apoptosis. To gain insights into the mechanisms regulating sperm survival after ejaculation, the role of AKT was investigated in stallion spermatozoa using a specific inhibitor and a phosphoflow approach. Stallion spermatozoa were washed and incubated in Biggers-Whitten-Whittingham medium, supplemented with 1% polyvinyl alcohol (PVA) in the presence of 0 (vehicle), 10, 20 or 30 μM SH5, an AKT inhibitor.

Autophagy and apoptosis have a role in the survival or death of stallion spermatozoa during conservation in refrigeration.

Apoptosis has been recognized as a cause of sperm death during cryopreservation and a cause of infertility in humans, however there is no data on its role in sperm death during conservation in refrigeration; autophagy has not been described to date in mature sperm. We investigated the role of apoptosis and autophagy during cooled storage of stallion spermatozoa. Samples from seven stallions were split; half of the ejaculate was processed by single layer centrifugation, while the other half was extended unprocessed, and stored at 5°C for five days.