The nociceptive systems of skin, paravascular tissue and hand veins of humans and their sensitivity to bradykinin.

To study the pain-evoking properties of bradykinn on the nociceptive systems of skin, paravascular tissue and hand veins of humans, bradykinin was injected intracutaneously, retrogradially into occluded finger veins for reaching the paravascular tissue or into vascularly isolated hand vein segments of seven subjects. Regardless of the injection site, bradykinin always evoked pain of concentration-related intensity within nearly similar concentration ranges of 0.1-10.0 microM, yielding congruent pain intensity-concentration relations. Thus, in humans, the nociceptive systems of skin, deep tissue and hand veins are equally sensitive to the endogenous algetic bradykinin.