endothelin-1 and Dermatitis

Endothelin (ET-1) has been shown to crucially contribute to UV-induced skin responses such as tanning. To test whether ET-1 is also involved in early cutaneous reactions to UV, we assessed ET-1 skin levels in UV-irradiated mice. In correlation with the levels of UV-induced skin inflammation, ET-1 concentrations increased substantially and continually. Moreover, blocking of ET-1 receptors (ETA) resulted in significantly decreased cutaneous inflammation following UV irradiation. When we assessed skin responses to ET-1 injections, we observed prominent mast cell degranulation and mast cell-dependent inflammation. Since mast cells also critically contributed to UV-induced inflammation, we determined the ET-1-dependent inflammatory response to UV in the absence and presence of these cells. Interestingly, ETA blockade did not decrease UV-induced inflammation in mast cell-deficient mice, unless these mice had been adoptively transferred with mast cells before irradiation. This indicates that skin inflammation due to UV irradiation is caused in part by ET-1 acting on skin mast cells.

Topics: Animals; Cell Degranulation; Dermatitis; Dose-Response Relationship, Radiation; Endothelin A Receptor Antagonists; Endothelin-1; Inflammation; Mast Cells; Mice; Mice, Transgenic; Receptor, Endothelin A; Ultraviolet Rays

In complex regional pain syndrome type 1 (CRPS1) pro-inflammatory mediators and vascular changes play an important role in the sustained development and outcome of the disease. The aim of this study was to determine the involvement of vasoactive substances endothelin-1 (ET-1) and nitric oxide (NO) during early chronic CRPS1.. Included were 29 patients with CRPS 1 who were diagnosed during the acute stage of their disease and observed during follow-up visits. Disease activity and impairment were determined and artificial suction blisters were made on the CRPS1 and the contralateral extremities for measurements of IL-6, TNF-alpha, ET-1 and nitrate/nitrite (NOx).. The levels of IL-6, TNF-alpha and ET-1 in blister fluid in the CRPS1 extremity versus the contralateral extremity were significantly increased and correlated with each other, whereas NOx levels were decreased.. The NOx/ET-1 ratio appears to be disturbed in the intermediate stage of CRPS, resulting in vasoconstriction and consequently in a diminished tissue blood distribution.

Topics: Adult; Biomarkers; Blister; Dermatitis; Down-Regulation; Endothelin-1; Female; Humans; Inflammation Mediators; Interleukin-6; Male; Microcirculation; Middle Aged; Nitric Oxide; Predictive Value of Tests; Reflex Sympathetic Dystrophy; Regional Blood Flow; Skin; Tumor Necrosis Factor-alpha; Up-Regulation