Lipoxygenase products of arachidonic acid in human inflamed skin.
Monohydroxy acids (HETEs) and leukotriene B4 (LTB4) metabolites of arachidonic acid were measured in skin of healthy volunteers after ultraviolet B irradiation, and in the uninvolved skin of psoriatics after topical dithranol application. Exudate was collected from suction bullae on control and inflamed abdominal skin, and analysed for 12-HETE and PGE2 by GC-MS and LTB4 by bioassay. 12-HETE and PGE2 were raised at 24 h but not at 72 h after u.v.B irradiation: control and 24 h values were 13.7 and 41.5 ng ml-1 (P less than 0.05, n = 6) for 12-HETE respectively, and 4.5 and 30.2 ng ml-1 (P less than 0.01, n = 6) for PGE2. Dithranol application raised PGE2 levels from 23.1 ng ml-1 in control exudate to 62 ng ml-1 (P less than 0.01, n = 6) at 24 h before declining to base levels at 72 h. However, 12-HETE was raised at 72 h (200 ng ml-1, P less than 0.01, n = 5) but not at 24 h (104 ng ml-1) compared to control levels (50 ng ml-1, n = 5). The levels of the LTB4 were low (less than 100 pg ml-1), and no significant increases were observed. Arachidonic acid in inflamed skin can be metabolised by the cyclo-oxygenase and lipoxygenase pathway. It is probable that the lipoxygenase product 12-HETE is involved in these inflammatory reactions.
D019377:12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; D000328:Adult; D000875:Anthralin / Q000494:pharmacology; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000378:metabolism*; D015232:Dinoprostone; D006801:Humans; D006893:Hydroxyeicosatetraenoic Acids / Q000378:metabolism; D007249:Inflammation / Q000201:enzymology / Q000209:etiology / Q000378:metabolism*; D007975:Leukotriene B4 / Q000378:metabolism; D008084:Lipoxygenase / Q000378:metabolism*; D008297:Male; D011458:Prostaglandins E / Q000378:metabolism; D011565:Psoriasis / Q000201:enzymology / Q000378:metabolism; D011832:Radiation Injuries / Q000201:enzymology / Q000378:metabolism; D012867:Skin / Q000201:enzymology / Q000378:metabolism*; D013997:Time Factors; D014466:Ultraviolet Rays
D001095:Arachidonic Acids; D006893:Hydroxyeicosatetraenoic Acids; D011458:Prostaglandins E; D007975:Leukotriene B4; D016718:Arachidonic Acid; D019377:12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; D008084:Lipoxygenase; D015232:Dinoprostone; D000875:Anthralin