Expression of angiopoietins 1, 2 and their common receptor tie-2 in relation to the size of endothelial lining gaps and expression of VEGF and VEGF receptors in idiopathic menorrhagia.

Objective: To investigate whether idiopathic menorrhagia (IM) is associated with alterations of the vascular expression of angiopoietin-1, angiopoietin-2, and tie-2 receptor.
Design: Prospective clinical study.
Setting: University Hospital, Department of Gynecology.
Patient(s): Twenty-four patients with IM and 18 women with eumenorrhea.
Intervention(s): Endometrial samples underwent immunohistochemical staining for CD34, angiopoetin-1, angiopoietin-2, tie-2, and smooth muscle actin-alpha. Previously published data on gap size and expression of vascular endothelial growth factor family members were used.
Main Outcome Measure(s): Differences in immunostaining for these markers by computer-assisted stereological analysis.
Result(s): There was significantly more angiopoetin-1 positive vessels in IM in the secretory phase, but not of angiopoetin-2 and tie-2, compared with controls. Densities of angiopoetin-1 positive vessels correlated significantly to those of angiopoetin-2 and vascular endothelial growth factor receptor 3. Smooth muscle actin-alpha positive pericytes covered the gaps. Double staining for CD34 and tie-2 receptor was partly identical, but gaps were covered by tie-2 stain.
Conclusion(s): The discrete deregulation observed of the angiopoetin-1 expression before menstruation might affect vascular integrity, thereby contributing to the excessive blood loss in IM.
(Copyright 2010 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.)