Bradykinin and electrical stimulation increase prostaglandin production inthe rat vas deferens

The epididymal portion of the rat vas deferens produced prostaglandins (PG) E-2, F-2 alpha and 6-keto F-1 alpha, Electrical stimulation (ES, 0.1 Hz,1 ms) increased such production by 100%, and similar results were obtained in the presence of 1.0 muM bradykinin (Bk). When both stimuli were applied si multaneously, the increases in PG production were 1100% for PGE(2), 800% fo r PGF(2 alpha) and 400% for PG6-keto F-1 alpha. Prazosin abolished the eff ect of ES on PG production. A selective Bk B-2-receptor antagonist abolishe d the increase in PG production induced by Bk, both in non-stimulated and i n ES tissues. Bk (1.0 muM) elicited contractile responses in non-stimulated as well as in ES tissues, responses that were not modified in the presence of 10 muM indomethacin. In conclusion, the effects of Bkon prostaglandin p roduction appears to depend on the activation of B-2 receptors, while the i ncrease in prostaglandin release induced by ES, and the effects observed wi th both stimuli simultaneously, should be mediated by the release of noradr enaline and the subsequent activation of alpha (1) adrenoceptors. (C) 2001 Harcourt Publishers Ltd.