Variations in metabolic parameters of matured porcine oocytes after vitrification-warming.

Background: As the porcine oocyte is the most sensitive to low-temperature damage, it has been difficult to cryopreserve compared to those from other domestic animals. However, at present, vitrification is used as a method for the cryopreservation of both oocytes and embryos in this species.

Aim: Our aim was to analyze alterations in metabolic parameters in vitrified-warmed matured porcine oocytes at different post-warming recuperation times.

Aggregation of Leopardus geoffroyi hybrid embryos with domestic cat tetraploid blastomeres.

Heterospecific embryo transfer of an endangered species has been carried out using recipients from related domestic females. Aggregation of an embryo from an endangered species with a tetraploid embryo from the species to be transferred could improve the development of pregnancy to term. The main objective of the present study was to analyze embryo aggregation in domestic cat model using hybrid embryos.

Implications of glycolytic and pentose phosphate pathways on the oxidative status and active mitochondria of the porcine oocyte during IVM.

Glycolysis and the pentose phosphate pathway (PPP) were modulated in porcine cumulus-oocyte complexes during IVM by the addition of inhibitors and stimulators of key enzymes of the pathways to analyze their influence on the oxidative status, active mitochondria, and maturation of the oocyte. The influence of pharmacologic and physiological inhibitors of glycolysis (Sodium fluoride and ATP) and PPP (6-Aminonicotinamide and nicotinamide adenine dinucleotide phosphate) was validated by assessing glucose and lactate turnover and brilliant cresyl blue staining in oocytes. Inhibitors of glycolysis and PPP activity significantly perturbed nuclear maturation, oxidative metabolism (Redox Sensor Red CC-1), and active mitochondria (Mitotracker Green FM) within oocytes (P < 0.

Pentose phosphate pathway activity: effect on in vitro maturation and oxidative status of bovine oocytes.

The relationship between pentose phosphate pathway (PPP) activity in cumulus-oocyte complexes (COCs) and oxidative and mitochondrial activity in bovine oocytes was evaluated with the aim of analysing the impact of two inhibitors (NADPH and 6-aminonicotinamide (6-AN)) and a stimulator (NADP) of the key enzymes of the PPP on the maturation rate, oxidative and mitochondrial activity and the mitochondrial distribution in oocytes. The proportion of COCs with measurable PPP activity (assessed using brilliant cresyl blue staining), glucose uptake, lactate production and meiotic maturation rate diminished when 6-AN (0.1, 1, 5 and 10mM for 22h) was added to the maturation medium (P<0.

Glycolytic pathway activity: effect on IVM and oxidative metabolism of bovine oocytes.

The aim of the present study was to determine the effect of altering glycolytic pathway activity during bovine IVM on the meiotic maturation rate, oxidative activity, mitochondrial activity and the mitochondrial distribution within oocytes. Glycolytic activity was manipulated using two inhibitors (ATP, NaF) and a stimulator (AMP) of key enzymes of the pathway. Inhibition of glucose uptake, lactate production and meiotic maturation rates was observed when media were supplemented with ATP or NaF.

Influence of hyaluronic acid synthesis and cumulus mucification on bovine oocyte in vitro maturation, fertilisation and embryo development.

During cumulus-oocyte complex (COC) maturation, cumulus expansion involves the deposition of mucoelastic compounds, especially hyaluronic acid, synthesised from glucose via the hexosamine biosynthesis pathway. The aim of the present study was to determine the effects of uridine monophosphate (UMP) and 6-diazo-5-oxo-L-norleucine (DON), inhibitors of hyaluronic acid synthesis, during bovine oocyte in vitro maturation (IVM) on cumulus expansion, glucose uptake, protein synthesis, cumulus cell number, meiotic maturation, cleavage rate and subsequent embryo development. A further aim of the study was to examine the effect of hyaluronic acid on sperm capacitation and acrosome reaction in relation to the capacity of COCs to be fertilised in vitro.