Retinoids inhibit bradykinin B-1 receptor-sensitized responses in human umbilical vein

Bradykinin B-1 receptors are not expressed under physiological conditions b ut are induced under inflammatory conditions. In isolated human umbilical v ein, a spontaneous bradykinin B-1 receptor sensitization process has been d emonstrated. On the other hand, retinoids have been shown to exert anti-inf lammatory and immunomodulatory actions. We have now examined the effects of all-trans-retinoic acid and 9-cis-retinoic acid on the bradykinin B-1 rece ptor-sensitized responses in human umbilical vein. Both retinoids produced a concentration-dependent rightward shift of the concentration-response cur ves for the bradykinin B-1 receptor agonist, des-Arg(9)-bradykinin. Retinoi d treatment did not modify the responses to bradykinin B-1 receptor-unrelat ed agonists, bradykinin or serotonin. In conclusion, retinoids inhibit brad ykinin B-1 receptor-sensitized responses and this action could participate in their anti-inflammatory and immunomodulatory effects. (C) 2000 Elsevier Science B.V. All rights reserved.