Cutaneous blood flow changes and weal induced by intradermal bradykinin following pretreatment with indomethacin and captopril.

The effects of indomethacin and captopril on local cutaneous blood flow changes and weal induced by intradermal injections of bradykinin were assessed in two randomised, double-blind, placebo-controlled studies in healthy volunteers. Alterations in cutaneous blood flow were estimated by laser Doppler flowmetry (LDF) and erythema area. LDF output, erythema area and weal volume increased with incremental bradykinin dose. Single doses of indomethacin 25 mg and 75 mg did not affect these cutaneous responses compared with placebo. Captopril 25 mg significantly potentiated the increase in local cutaneous blood flow measured by LDF, but not erythema area, and weal volume induced by bradykinin. The effects of the combined treatment of indomethacin 75 mg and captopril 25 mg were not significantly different from those due to captopril alone. The enhanced cutaneous effects of bradykinin following administration of captopril are in keeping with effective kininase II inhibition in the tissues. Cyclo-oxygenase products release does not appear to contribute to the cutaneous actions of bradykinin nor the potentiation of these responses by captopril.