INTRADERMAL LEUKOTRIENE B-4, BUT NOT PROSTAGLANDIN E-2, INDUCES ITCH-ASSOCIATED RESPONSES IN MICE

The itch-associated responses induced by intradermal injection of leuk otriene B-4 and prostaglandin E were studied in mice. Leukotriene B-4 (0.001-1 nmol/site) elicited scratching of the injected site; the dose -response curve was bell-shaped with a peak effect at 0.03 nmol/site. The effect of leukotriene B-4 (0.03 nmol/site) started within 3 min, p eaked in the second l0-min period, had almost subsided by 30 min, and was inhibited by the simultaneous injection of the leukotriene B-4 rec eptor antagonist ONO-4057, 2-carboxyethyl)-3-(6-(p-methoxyphenyl)-5E-h exenyl) oxyphenyoxy] valeric acid. Prostaglandin E-2 (0.003-300 nmol/s ite) did not significantly elicit scratching. The results raise the po ssibility that leukotriene B-4 is an endogenous itch mediator in the s kin. (C) 1998 Elsevier Science B.V. All rights reserved.