Microvascular density, vascular endothelial growth factor A, and its receptors in endometrial blood vessels in patients with menorrhagia.

Objective: To analyze the expression of vascular endothelial growth factor A (VEGF-A) and receptors (VEGFR-1 and VEGFR-2) in endometrial blood vessels, as well as microvascular density (MVD), in endometrial biopsy samples from idiopathic menorrhagia patients.

Design: Prospective clinical study.

Setting: University hospital, unit of gynecology.

Patient(s): Twenty-four patients with idiopathic menorrhagia and 18 healthy fertile women.

Intervention(s): Blood sampling for hormone measurement, hysteroscopy, and endometrial biopsy sampling. Endometrial biopsy samples were used for immunohistochemistry assessments and image analysis of stained endothelial structures for VEGF-A, VEGFR-1, VEGFR-2, and CD34.

Main Outcome Measure(s): Appearance of the endometrial vascular immunoreactivity for VEGF-A, VEGFR-1, and VEGFR-2, MVD and computer-assisted stereological analysis of immunoassayed blood vessels.

Result(s): Although the MVD did not differ between patients and controls, we observed that vascular expression of VEGF-A, VEGFR-1, and VEGFR-2 in capillaries was 1.8-fold, 1.8-fold, and 2.0-fold higher, respectively, in the menorrhagia group when assessed as the number of stained capillaries per unit area. There were also a twofold higher number of arterioles, which were VEGFR-2 positive in the menorrhagia group.

Conclusion(s): Up-regulation of VEGF-A and receptors VEGFR-1 and VEGFR-2 in capillaries in menorrhagia could be involved in abnormal endometrial vascular structure and permeability.