OCCURRENCE OF HEPOXILINS AND TRIOXILINS IN PSORIATIC LESIONS

We recently found that normal human epidermis produces relatively high amounts of hepoxilins and trioxilins in vitro. Therefore, the aim of this study was to demonstrate the presence of these compounds in psori atic lesions. Extracts front scales of patients with chronic stable pl aque psoriasis were analyzed by a combination of high performance liqu id chromatography and gas chromatography-mass spectrometry techniques, We found that the levels of hepoxilin B-3 were more than 16-fold high er in psoriatic scales than in normal epidermis (3.2 +/- 2.3 and < 0.2 ng per mg, respectively), whereas hepoxilin A(3) was not detected in ally sample, Trioxilins were semiquantitated and referred to 12-hydrox yeicosatetraenoic acid, ratios of trioxilins A(3) and B-3 12-hydroxyei cosatetraenoic acid in psoriatic lesions were 0.65 +/- 0.23 and 0.32 /- 0.28, respectively, and they were not detected in normal epidermis, The presence of a great amount of trioxilin A(3) strongly suggests th at hepoxilin A(3) was present in psoriatic lesions and it was totally degraded to trioxilin A(3), during the analysis procedure, Our results demonstrate that hepoxilins and trioxilins are produced by human skin in vivo and that the levels of these compounds are increased in psori asis, The reported biologic activities of hepoxilins indicate that the y could amplify and maintain the inflammatory response, Our results re inforce the idea that these compounds could play a role as mediators i n the inflammatory response in skin, particularly in psoriasis.