Total urokinase-type plasminogen activator (uPA) levels in seminal plasma are associated with positive assisted reproductive technology outcomes.

Purpose: The plasminogen/plasmin system is an important extracellular protease system whose function has been implicated in male reproductive function. However, its clinical relevance to fertility in human assisted reproduction technologies has not been systematically investigated. Here, we examined whether total and active populations of urokinase-type plasminogen activator (uPA) in human seminal plasma and spermatozoa are predictive of pregnancy outcome in couples undergoing insemination or intracytoplasmic sperm injection (ICSI).

Calreticulin from suboolemmal vesicles affects membrane regulation of polyspermy.

This study was designed to determine whether calreticulin (CRT), a chaperone protein, is present in in vitro-matured (IVM) pig oocytes and to study its potential role in the block to polyspermy. Western blot analysis, using an anti-CRT antibody, of oocyte lysate showed an immunoreactive band of ∼60  kDa. Simultaneous labeling of IVM oocytes with anti-CRT antibody and peanut agglutinin lectin (PNA lectin, a porcine cortical granules (CG)-specific binding lectin) revealed localization of CRT in the subplasmalemmal region with a 27.

Identification of potential oviductal factors responsible for zona pellucida hardening and monospermy during fertilization in mammals.

Oviduct fluid increases the time required for digestion of the zona pellucida (ZP) by proteolytic enzymes (ZP hardening). This effect has been associated with levels of monospermy after in vitro fertilization (IVF) in the pig and cow, but the possible existence of a directly proportional relationship between hardening and monospermy remains unknown. To investigate whether variations in hardening of different oviductal fluids (OFs) are correlated with variations in levels of monospermy after IVF, porcine oocytes were incubated with three batches of OFs known to produce different ZP hardening effects (3, 7, and 25 min); after IVF, monospermy levels were 0%, 14.

How is plasminogen/plasmin system contributing to regulate sperm entry into the oocyte?

Plasminogen is present in the oviduct, on the zona pellucida (ZP) and on oolemma, and reduces the number of sperm penetrating the oocyte during in vitro fertilization in pig and cow. It is unknown how this reduction occurs. We tested whether plasminogen (1) changed the ZP resistance to enzymatic digestion thus making the passage of the spermatozoa across it difficult; (2) reduced the sperm functionality, assessed by sperm viability, motility, spontaneous acrosome reaction and membrane lipid disorder; or (3) affected the sperm-ZP binding before or after sperm-ZP interaction.

Oocytes use the plasminogen-plasmin system to remove supernumerary spermatozoa.

Background: The role of the plasminogen-plasmin (PLG-PLA) system in fertilization is unknown, although its dysfunction has been associated with subfertility in humans. We have recently detected and quantified plasminogen in the oviductal fluid of two mammals and showed a reduction in sperm penetration during IVF when plasminogen is present. The objective of this study was to describe the mechanism by which PLG-PLA system regulates sperm entry into the oocyte.

Fertilization outcome could be regulated by binding of oviductal plasminogen to oocytes and by releasing of plasminogen activators during interplay between gametes.

Objective: To detect plasminogen and plasminogen activators (PA) in oviduct and oocytes and to clarify the role of the plasminogen/plasmin system on mammalian fertilization.

Design: Experimental prospective study.

Setting: Mammalian reproduction research laboratory.

Oviduct-specific glycoprotein and heparin modulate sperm-zona pellucida interaction during fertilization and contribute to the control of polyspermy.

Polyspermy is an important anomaly of fertilization in placental mammals, causing premature death of the embryo. It is especially frequent under in vitro conditions, complicating the successful generation of viable embryos. A block to polyspermy develops as a result of changes after sperm entry (i.