Since premature luteinization is very unlikely to occur under the conditions of this study, our findings suggest that an early PP rise has a negative impact on endometrial receptivity but not on egg and embryo quality.

No abstract

The purpose of the present study was to investigate the distribution pattern of carbo-hydrates in the zona pellucida of human oocytes using lectins and ruthenium red as histochemical probes. For (SBA) did not bind at all. There was almost no binding of ruthenium red to the matrix of the zona pellucida. The results indicate that the human zona pellucida is characterized by normally exposed mannosyl, N-acetylglucosaminyl and \g=b\-galactosyl residues. In addition, it contains masked \g=b\Gal-(1\p=n-\3)GalNAcsugar sequences that can be exposed only after removing terminal sialic acid residues. The presence of sialic acid in the human zona pellucida, which is not expressed as an increase in the binding capacity of the polycationic probe (ruthenium red), has not been reported in any of the mammalian zonae pellucidae previously studied.

No abstract