Localization of Bradykinin B2Receptors in the Endometrium and Myometrium of Rat Uterus and the Effects of Estrogen and Progesterone1

In the uterus, bradykinin is a potent inducer of smooth muscle contraction, which is mediated by the bradykinin B2 receptor subtype. However, little is known about the distribution or regulation of this receptor in this tissue. The aim of this study was to localize the B2 receptor in the uterus and determine whether the levels of this receptor were altered during the estrous cycle and modulated by estrogen and/or progesterone in ovariectomized rats. At diestrus, uterine B2 receptors were localized to both the circular and longitudinal smooth muscle layers of the myometrium, the endometrial stroma, the glandular epithelium, and the layer subjacent to the luminal epithelium. B2 receptor level…