POTENTIATION OF ITCH AND FLARE RESPONSES IN HUMAN-SKIN BY PROSTAGLANDINS E-2 AND H-2 AND A PROSTAGLANDIN ENDOPEROXIDE ANALOG

[摘要] The itch and erythematous responses induced by intradermal injection of prostaglandin E2 (PGE2), the unstable prostaglandin endoperoxide PGH2 (t1/2 [half-life] .apprx. 5 min at 37.degree. C) and the stable endoperoxide analog (15S)-hydroxy-9.alpha., 11.alpha.-(epoxymethano)prosta-5,13-dienoic acid (EPA) were studied in volunteers. The compounds were given alone or in combination with histamine. All the compounds produced flare reaction in the skin; the order of potency was PGE2 > PGH2 > EPA. PGE2 and PGH2 evoked a sensation of itch in about half of the subjects; the same doses of EPA gave no itch response. In combination with histamine all compounds elicited itch of longer duration and flare of larger area than could be accounted for by simple additive effects of any released histamine. The PG and PG intermediates formed in skin may potentiate the pruritogenic and flare-inducing effects of inflammagens in man.