Background: Endometrial angiogenesis is important for bleeding control and fertility, and is believed to be regulated by angiogenic growth factors under the influence of ovarian steroids.
Objective: To document the pattern of expression of the two angiogenic growth factors, vascular endothelial growth factor (VEGF)-B and VEGF-C, and of their receptors, VEGFR-1, VEGFR-2, and VEGFR-3, in order to investigate their possible role in the regulation of angiogenesis in normal cycling human endometrium.
Material and methods: Cryosections of endometrial biopsy specimens obtained from 17 healthy women before laparoscopic sterilization were examined by immunohistochemistry.
Results: Vascular endothelial growth factor and VEGF-C and their receptors were all expressed in and around endometrial blood vessels, with no obvious menstrual cycle-dependent changes in expression except for VEGFR-2, which showed stronger expression during the early secretary phase. Stromal blood vessel density did not change significantly during the menstrual cycle.
Conclusion: The presence and pattern of expression of these angiogenic growth factors and their receptors suggest that they participate in the regulation of normal endometrial angiogenesis.