Prostaglandin E2and nitric oxide mediate the acute inflammatory (erythemal) response to topical 5-aminolaevulinic acid photodynamic therapy in human skin
التفاصيل البيبلوغرافية
العنوان:
Prostaglandin E2and nitric oxide mediate the acute inflammatory (erythemal) response to topical 5-aminolaevulinic acid photodynamic therapy in human skin
Summary Background Topical 5-aminolaevulinic acid photodynamic therapy (5-ALA-PDT) causes a clinical inflammatory response in human skin. While histamine mediates the immediate reaction, the mediators of the prolonged erythema are unknown. Objectives To look for involvement of the proinflammatory mediators prostaglandin (PG)E2 and nitric oxide (NO) in topical PDT-induced erythema in human skin. Methods A series of studies was performed in healthy volunteers (n = 35). Following definition of the erythemal time course and dose response to 5-ALA-PDT, duplicate 5-ALA dose series were iontophoresed into the skin of each ventral forearm and exposed to 100 J cm−2 broadband red light. Within subject, arms were randomized to control, or treatment with the cyclooxygenase and NO synthase inhibitors indometacin and Nω-nitro-l-arginine methyl ester (l-NAME), respectively, and the impact on 5-ALA-PDT-induced erythema was quantified. Additionally, release of PGE2 and NO was directly assessed by sampling dermal microdialysate at intervals following 5-ALA-PDT administration. Results A 5-ALA dose-related delayed erythema occurred by 3 h (r = 0·97, P
