Involvement of Tryptase and Proteinase-Activated Receptor-2 in Spontaneous Itch-Associated Response in Mice With Atopy-like Dermatitis.

This study investigated the involvement of tryptase and proteinase-activated receptor (PAR) subtypes in spontaneous scratching, an itch-associated behavior, in NC mice. This strain of mice showed chronic atopy-like dermatitis and severe spontaneous scratching, when kept a long time in a conventional environment. The trypsin-like serine proteinase inhibitor nafamostat mesilate (1 - 10 mg/kg) dose-dependently inhibited spontaneous scratching in mice with dermatitis.

Potent pruritogenic action of tryptase mediated by PAR-2 receptor and its involvement in anti-pruritic effect of nafamostat mesilate in mice.

The pruritogenic potency of tryptase and its involvement in anti-pruritic effect of intravenous nafamostat mesilate (NFM) were studied in mice. An intradermal injection of tryptase (0.05-1 ng/site) elicited scratching in ICR mice, while chymase was without effects at doses of 0.