Changes in Uterine Microvessels as a Possible Pathogenic Factor in the Development of Adenomyosis Induced by Pituitary Grafting in Mice.

Abstract

Changes in uterine blood vessels were evaluated quantitatively by an immunohistochemical study using an antibody to von Willebrand factor (vWF) during the development of experimentally induced adenomyosis in mice. In all mice treated with pituitary grafting, which is a useful method of inducing adenomyosis, slight adenomyosis was found near the mesometrium 4 weeks after the operation. In the uteri with adenomyosis, the mean surface area and minor axis of blood vessels increased significantly in the endometrium and showed a tendency to increase in the myometrium, while the mean number of blood vessels in both endometrium and myometrium decreased significantly compared with those in the normal uteri. The mean percentage of total surface area of blood vessels to mean total tissue area of either endometrium or myometrium was not different in the two groups. Remarkably dilated venules in the endometrium were frequently found in pituitary-grafted mice. In the myometrium, the mean percentage of surface area and mean number of blood vessels were greater in the mesometrial side than in the antimesometrial side in both the control and pituitary-grafted mice. Thus, pituitary grafting significantly increased the number of dilated venules and decreased the number of microvessels in the uterus, suggesting that vascular changes may be one of the important etiological factors for the development of adenomyosis.