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A study of the photodegradation of leukotriene B 4 by ultraviolet irradiation (UVB, UVA)
Author(s) -
MILLAR B.,
GREEN C.,
FERGUSON J.,
RAFFLE E.J.,
MACLEOD T.M.
Publication year - 1989
Publication title -
british journal of dermatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.304
H-Index - 179
eISSN - 1365-2133
pISSN - 0007-0963
DOI - 10.1111/j.1365-2133.1989.tb07778.x
Subject(s) - leukotriene b4 , psoriasis , irradiation , erythema , chemotaxis , chemistry , dose , dermatology , medicine , immunology , pharmacology , inflammation , biochemistry , physics , receptor , nuclear physics
SUMMARY In view of the presence of the polymorphonuclear leukocyte (PMN) chemoattractant Leukotriene B 4 (LTB 4 ) in the surface scale of the psoriatic lesion and the known therapeutic effect of phototherapy in psoriasis, the photostability of LTB 4 was investigated. LTB 4 was irradiated with dosages of UVB (290–320 nm) ranging from 100–1500 mJ cm −2 and with dosages of UVA (320–400 nm) ranging from 5–40 J cm −2 . Topical application of UVB irradiated LTB 4 to the forearm skin of normal volunteers showed a marked reduction in cutaneous erythema, paralleled histologically by reduced transepidermal PMN migration when compared with sites of application of unirradiated and UVA irradiated LTB 4 . High performance liquid chromatography (HPLC) demonstrated a dose‐dependent photodegradation of LTB 4 by UVB irradiation. UVA irradiation produced no such effect. The wavelengths responsible lie within the absorption spectrum of LTB 4 . In vitro chemotaxis studies, using an under agarose technique, showed a statistically significant reduction in the migration of PMN from both psoriatic and non‐psoriatic subjects to the UVB irradiated LTB 4 compared with the unirradiated LTB 4 , whilst UVA irradiated LTB 4 produced a normal PMN chemotactic response.