ABSTRACT
Vascular permeability and angiogenesis are crucial events in the rodent and human uterus
in early pregnancy and are regulated by vascular endothelial growth factor (VEGF) and
prostaglandins liberated from arachidonic acid by cyclooxygenase 2 (COX2). These
events coincide with the typical morphological features of the receptive uterus and are
regulated by synchronized release of ovarian hormones (oestrogen and progesterone).
However, administration of follicle stimulating hormone (FSH) and human chorionic
gonadotropin (hCG), commonly used in assisted reproduction, affect the synchrony of the
hormonal milieu, particularly by increasing oestrogen levels. This causes detrimental
changes to the uterine morphology and affects vascular permeability at the site of
implantation. In the present study, the expression of COX2 and VEGF was compared
between control and hyperstimulated rat uteri during the peri-implantation period using immunohistochemistry and Western blot analysis.
While in control pregnant rats COX2 and VEGF immunolocalization occurred in the
luminal epithelial cells and stroma on consecutive days, strong immunolocalization of
COX2 and VEGF occurred in the luminal epithelial cells but was inhibited in the stroma
of the hyperstimulated rats. This appears to have resulted in the suppression of stromal
decidualization and vascular permeability. Western blot analysis did not show any
results. This may be due to low concentrations of the protein in the sample. Since
vascular permeability and angiogenesis are critical to the process of implantation and are
influenced by VEGF and COX2, disturbance of the pattern of these two proteins by
hyperstimulation may contribute to the low implantation rate in IVF programes. immunohistochemistry and Western blot analysis.
While in control pregnant rats COX2 and VEGF immunolocalization occurred in the
luminal epithelial cells and stroma on consecutive days, strong immunolocalization of
COX2 and VEGF occurred in the luminal epithelial cells but was inhibited in the stroma
of the hyperstimulated rats. This appears to have resulted in the suppression of stromal
decidualization and vascular permeability. Western blot analysis did not show any
results. This may be due to low concentrations of the protein in the sample. Since
vascular permeability and angiogenesis are critical to the process of implantation and are
influenced by VEGF and COX2, disturbance of the pattern of these two proteins by
hyperstimulation may contribute to the low implantation rate in IVF programes.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:wits/oai:wiredspace.wits.ac.za:10539/5586 |
| Date | 02 September 2008 |
| Creators | Strkalj, Mirjana |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | application/pdf |
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