Immunohistochemical localisation of prostaglandin endoperoxide synthase and prostacyclin synthase in pregnant human myometrium.

The localisation of prostaglandin endoperoxide synthase and prostacyclin synthase in pregnant human myometrium was examined by indirect immunocytofluorescent staining using monoclonal antibodies raised against these enzymes. Both enzymes were demonstrated to be present in myometrial smooth muscle cells. Staining associated with prostacyclin synthase, however, was more intense throughout the myometrium and less circumscript than that associated with prostaglandin endoperoxide synthase. The findings indicate that the uterine smooth muscle cells themselves possess the enzymes necessary for producing prostacyclin from arachidonic acid and that this capacity is not limited to the uterine macro- and microvasculature.