The fine structure of the human ovarian vein.

The human ovarian vein is of particular interest as an adult vessel which changes with the different phases of reproductive life. At the ultrastructural level we have characterised the endothelium, vascular smooth muscle and autonomic innervation of the human ovarian vein. Transmission electron micrographs were prepared from surgical specimens of the human ovarian vein (n = 11) to demonstrate the features of the vessel wall. The pattern of innervation was investigated using an image analysis system which was also used with high-magnification micrographs to count and measure axonal vesicle types. Possible relationships between ultrastructural features and age and reproductive history were investigated. Endothelial cells contained Weibel-Palade bodies and numerous microfilaments. There were 3 muscle coats: no elastic lamina separated the endothelium from an inner layer of smooth muscle; a middle smooth muscle layer consisted of cells orientated in a circular fashion; an outer smooth muscle layer was made up of longitudinally arranged smooth muscle bundles with collagen and nerves penetrating throughout. The percentage of the vessel thickness occupied by the middle circular smooth muscle layer ranged from 0 to 33% and fell with increasing age (r = -0.67, P < 0.05). Penetration of nerves into the circular layer was observed only in 2 of 9 specimens. The observed ultrastructural features are consistent with the ability of the ovarian vein to distend substantially in response to changing circulatory demands. The vascular endothelium may have a role in the local control of haemostasis via the synthesis and storage of von Willebrand factor.(ABSTRACT TRUNCATED AT 250 WORDS)