Aging, hyaluronidase removal of the cumulus, and microinjection do not affect the sperm binding potential of human oocytes

Barros, Alberto; Sousa, Mário; Silva, Joaquina; Almeida, Vasco; Rocha, Eduardo

doi:10.1007/bf02765778

Cited by 3 publications

(3 citation statements)

References 27 publications

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“…Therefore, oocytes from different patients were stored for up to 10 days in a hyperosmolaric salt solution. As demonstrated by Barros et al . (1997), ageing, previous insemination, cumulus removal by hyaluronidase and microinjection do not affect the sperm binding potential of human oocytes.…”

Section: Methodssupporting

confidence: 57%

Use of microbeads for the detection of binding sites on the human zona pellucida: a scanning electron microscopy (SEM) assay

Michelmann¹,

Töpfer‐Petersen

Schwartz

et al. 2001

Andrologia

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One prerequisite for fertilization is the specific binding of spermatozoa to the zona pellucida. However, the factors and mechanisms involved in this gamete contact are not well understood. Gamete recognition and binding are species-specific and are controlled by oligosaccharides of the zona and their corresponding carbohydrates on the spermatozoon. By using a specific lectin we developed a technique to detect those oligosaccharides on the human zona pellucida that might be involved in the binding process. Microbeads (Ø = 2.8 microm), used as artificial spermatozoa, were coated with lectin Con A and cultured together with 75 unfertilized oocytes (group A) remaining after intracytoplasmic sperm injection. Con A binds specifically to alpha-d-mannose and alpha-d-glucose. As a control, 75 unfertilized oocytes after intracytoplasmic sperm injection (group B) were also cultured together with Con A-covered microbeads, but in a medium containing a binding inhibiting sugar (alpha-methyl-mannopyrasosid). The number and distribution of the microbeads on human oocytes of both groups were analysed on scanning electron microscopy images. Beads on oocytes of group A had binding patterns similar to those of spermatozoa. They were distributed in an extremely heterogeneous way with various numbers of bound beads both on individual and different oocytes. Most of the group A oocytes (85%) had more than 50 beads bound to the zona, in contrast to the control oocytes of group B, where 68% had less than 10 bound beads. The use of an inhibiting sugar abolished the binding capacity of the microbeads nearly completely. This technique is a powerful tool for the detection of binding sites on the zona pellucida, i.e. those sugars that are responsible for contact between spermatozoa and the zona pellucida.

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Section: Methodssupporting

confidence: 57%

Use of microbeads for the detection of binding sites on the human zona pellucida: a scanning electron microscopy (SEM) assay

Michelmann¹,

Töpfer‐Petersen

Schwartz

et al. 2001

Andrologia

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“…During OPU, the retrieved cumulus–oocyte complexes (COCs) were washed in buffered medium (Flushing medium; Cook Ltd, Ireland) and denuded of CCs by gently pipetting in HEPES medium containing hyaluronidase (Synvitro Hyadase; Origio Medicult, Denmark) at a concentration of 80 IU/mL. 19 Among the COCs retrieved from these patients, 90 were randomly selected for the study: all contained mature oocytes in metaphase II and the CCs were isolated and stored at −30°C until analysis. These 90 CCs were divided into 2 groups as described in the following paragraphs.…”

Section: Methodsmentioning

confidence: 99%

Inducible Nitric Oxide Synthase and Heme Oxygenase 1 Are Expressed in Human Cumulus Cells and May Be Used as Biomarkers of Oocyte Competence

Bergandi

Basso²,

Evangelista³

et al. 2014

Reprod. Sci.

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The interplay between oocyte and surrounding cumulus cells (CCs) during follicular growth influences oocyte competence to undergo fertilization and sustain embryo development. The expression of many genes and proteins in CCs has been suggested as potential biomarker of oocyte competence in human in vitro fertilization (IVF). In the present study, we analyzed 90 human cumulus-oocyte complexes obtained during IVF procedure: 30 CCs were analyzed using quantitative real-time polymerase chain reaction and 60 CCs using Western blotting analysis to detect gene and protein expression of some enzymes related to oxidative stress, that is, the 3 nitric oxide synthase (NOS) isoforms and heme oxygenase 1 (HO-1). In the group of 60 CCs, we also investigated the expression and phosphorylation of IkBα, a known inhibitor of the nuclear factor κB (NF-κB) pathway, which controls several redox-sensitive genes. The expression of the messenger RNAs (mRNAs) was related to the oocyte morphological analysis performed by polarized light microscopy and to the occurrence of normal fertilization after intracytoplasmic sperm injection. We observed that the amount of iNOS and HO-1 mRNAs and proteins is significantly higher, and that in the meanwhile the NF-κB pathway is activated, in CCs corresponding to oocytes that were not fertilized in comparison to CCs whose corresponding oocyte showed normal fertilization. Instead, no correlation between the fertilization and the oocytes' morphological data was observed. These results suggest that the increase in iNOS and HO-1 mRNAs expression in CCs is a negative index of oocyte fertilizability and might be an useful tool for oocyte selection.

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“…Therefore, oocytes from different patients were stored for up to 10 days in a hyperosmolaric salt solution. As demonstrated by Barros et al (1997), ageing, previous insemination, cumulus removal by hyaluronidase and microinjection do not affect the sperm binding potential of human oocytes. Furthermore, Kruger et al (1991), as well as Yanagimachi et al (1979), Liu et al (1988) and Franken et al (1991), showed that the binding capacity of living oocytes did not differ from the binding capacity of salt-stored oocytes.…”

Section: Methodsmentioning

confidence: 87%

Use of microbeads for the detection of binding sites on the human zona pellucida: a scanning electron microscopy (SEM) assay

Michelmann¹,

Töpfer‐Petersen

Schwartz

et al. 2001

Andrologia

View full text Add to dashboard Cite

S u m m a r y . One prerequisite for fertilization is the specific binding of spermatozoa to the zona pellucida. However, the factors and mechanisms involved in this gamete contact are not well understood. Gamete recognition and binding are species-specific and are controlled by oligosaccharides of the zona and their corresponding carbohydrates on the spermatozoon. By using a specific lectin we developed a technique to detect those oligosaccharides on the human zona pellucida that might be involved in the binding process. hlicrobeads (0 = 2.8 pm), used as artificial spermatozoa, were coated with lectin Con A and cultured together with 75 unfertilized oocytes (group A) remaining after intracytoplasmic sperm injection. Con A binds specifically to a-D-mannose and a-D-glucose. As a control, 75 unfertilized oocytes after intracytoplasmic sperm injection (group B) were also cultured together with Con A-covered microbeads, but in a medium containing a binding inhibiting sugar (a-methyl-mannopyrasosid). The number and distribution of the microbeads on human oocytes of both groups were analysed on scanning electron microscopy images. Beads on oocytes of group A had binding patterns similar to those of spermatozoa. They were distributed in an extremely heterogeneous way with various numbers of bound beads both on individual and different oocytes. Most of the group A oocytes (85%) had more than 50 beads bound to the zona, in contrast to the control oocytes of group B, where 68% had less than 10 bound beads.

show abstract

Aging, hyaluronidase removal of the cumulus, and microinjection do not affect the sperm binding potential of human oocytes

Cited by 3 publications

References 27 publications

Use of microbeads for the detection of binding sites on the human zona pellucida: a scanning electron microscopy (SEM) assay

Use of microbeads for the detection of binding sites on the human zona pellucida: a scanning electron microscopy (SEM) assay

Inducible Nitric Oxide Synthase and Heme Oxygenase 1 Are Expressed in Human Cumulus Cells and May Be Used as Biomarkers of Oocyte Competence

Use of microbeads for the detection of binding sites on the human zona pellucida: a scanning electron microscopy (SEM) assay

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