Release of prostaglandins by bradykinin as an intrinsic mechanism of its algesic effect

Abstract

The release of PGs from the isolated perfused rabbit ear was measured by means of a radioimmunoassay. Bradykinin in dose dependent amounts released mainly PGE (presumably PGE₁) and in much smaller amounts also PGF. Bradykinin released similar amounts of PGE in innervated and chronically denervated ears. Indomethacin completely prevented the PGE release by bradykinin. ACh showed a much lower efficacy than bradykinin in releasing PGE and PGF. Synthetic substance P was devoid of any PGE releasing action. It is concluded that bradykinin increases its own algesic action by a concomitant rapid stimulation of the PGE synthesis, thus providing a mechanism for the facilitation of its own algesic action.