title: A corticosteroid, a non-steroidal anti-inflammatory drug and an antihistamine modulate in vivo vascular reactions before and during post-occlusive hyperaemia.
abstract: Post-occlusive reactive hyperaemia is the temporary increase of blood flow in a tissue following transient vascular obstruction, and has recently been proposed as an in vivo method for ranking topical corticosteroid potency. We investigated in vivo vascular reactions before and during post-occlusive hyperaemia using laser-Doppler flowmetry and reflectance spectroscopy (RS). RS enables resolution of in vivo erythema into deoxygenated (venous) [DOH] and oxygenated (arterial) haemoglobin (OH) components (expressed in arbitrary units, AU). Using a randomized 24-h occlusive exposure in 10 healthy volunteers the effects of a corticosteroid (betamethasone-17-valerate), a non-steroidal anti-inflammatory drug (NSAID) [indomethacin], an antihistamine (diphenhydramine), or vehicle, were studied before and during post-occlusive hyperaemia. The 24-h vehicle exposure decreased total haemoglobin (composed of a small increase in OH [P < 0.001] and a greater decrease in DOH [P < 0.005], [OH, 0.23 +/- 0.18 AU; DOH, 0.28 +/- 0.12 AU]). The blood flow increased 7.1% to 28 +/- 8 AU (P > 0.05). Betamethasone-17-valerate exposure decreased total haemoglobin further (OH, 0.10 +/- 0.09 AU [P < 0.005]; DOH, 0.18 +/- 0.08 AU [P < 0.05]), which corresponded to a 15% blood flow decrease (P < 0.05). Indomethacin reduced OH to 0.18 +/- 0.12 AU (P < 0.02) and increased DOH slightly, with a trend towards decreased blood flow (P > 0.05). Diphenhydramine caused no significant changes in RS or laser-Doppler flowmetry readings before post-occlusive hyperaemia. Post-occlusive hyperaemia increased total haemoglobin maximally at the first observation time (OH, 0.63 +/- 0.13 AU; DOH, 0.31 +/- 0.11 AU [P < 0.001]).(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Dermatology, University of California School of Medicine, San Francisco 94143-0989.
authors.forename: P H
authors.initials: PH
authors.lastname: Andersen
authors.forename: P W
authors.initials: PW
authors.lastname: Broichmann
authors.forename: H
authors.initials: H
authors.lastname: Maibach
mesh_terms: D000328:Adult; D001624:Betamethasone Valerate / Q000494:pharmacology*; D001783:Blood Flow Velocity / Q000187:drug effects; D004155:Diphenhydramine / Q000494:pharmacology*; D005260:Female; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D006940:Hyperemia / Q000209:etiology; D007213:Indomethacin / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D010108:Oxyhemoglobins / Q000032:analysis; D012039:Regional Blood Flow / Q000187:drug effects; D012867:Skin / Q000098:blood supply*; D013053:Spectrophotometry; D013997:Time Factors; D014661:Vasoconstriction / Q000502:physiology*
chemical_list: D006454:Hemoglobins; D010108:Oxyhemoglobins; D004155:Diphenhydramine; D001624:Betamethasone Valerate; D007213:Indomethacin