INVESTIGATION INTO THE ROLE OF CYCLOOXYGENASE PRODUCTS IN THE BRADYKININ RESPONSE ON ISOLATED HUMAN MYOMETRIUM AND UMBILICAL ARTERY

The aim of this study was to investigate the response to bradykinin (B K) on human myometrium and umbilical artery with respect to cyclo-oxyg enase (GO) products. Dose/concentration response curves to BK were per formed +/-2.79 mu M indomethacin. On human myometrium the response to BK (0.001-50 nmol) was biphasic and consisted of a dose-related increa se in myometrial tension which was followed by a period of inhibition of myogenic activity. In tissues from P donors the presence of indomet hacin had no significant effect on the excitatory response, but the in hibitory component of the response was reduced. In tissues from NP don ors indomethacin significantly enhanced the BK effect at higher doses and the inhibitory component of the response was reduced. On the HUA c umulative addition of BK (1-1000 nM) resulted in dose dependent constr iction with desensitisation at the highest dose (EC(50) = 38 nM). The presence of indomethacin had no significant effect on BK response on H UA. These findings suggest that CO products contribute significantly t o response to BK on the human myometrium but not on HUA and that diffe rent CO products are produced by P and NP tissue.