Effects of calcium and EDTA on rat skin capillary permeability and on its response to histamine, serotonin and bradykinin.

Evans blue extravasation in rat skin was used to study the effects of Ca2+ and EDTA on vascular permeability and on its response to mediators of inflammation. Ca2+ induced a concentration-dependent decrease of vascular permeability. The opposite effect was seen with EDTA 0.2 mM or higher. Effects on vascular permeability of intradermically injected histamine 100 micrograms/ml, serotonin 5 micrograms/ml and bradykinin 5 micrograms/ml, were lower when Ca2+ 8 mM was injected in the same site, and higher when EDTA 2 mM was given. EDTA effects were inhibited by Ca2+. The results suggest that, in rat skin, Ca2+ decreases capillary permeability and its response to histamine, serotonin and bradykinin.