seryl-leucyl-isoleucyl-glycyl--arginyl-leucinamide and icatibant

Activation of the proteinase-activated receptor-2 (PAR-2) induces scratching behaviour in mice. Here, we have investigated the role of kinin B(1) and B(2) receptors in the pruritogenic response elicited by activators of PAR-2.. Scratching was induced by an intradermal (i.d.) injection of trypsin or the selective PAR-2 activating peptide SLIGRL-NH(2) at the back of the mouse neck. The animals were observed for 40 min and their scratching response was quantified.. I.d. injection of trypsin or SLIGRL-NH(2) evoked a scratching behaviour, dependent on PAR-2 activation. Mice genetically deficient in kinin B(1) or B(2) receptors exhibited reduced scratching behaviour after i.d. injection of trypsin or SLIGRL-NH(2). Treatment (i.p.) with the non-peptide B(1) or B(2)receptor antagonists SSR240612 and FR173657, respectively, prevented the scratching behaviour caused by trypsin or SLIGRL-NH(2). Nonetheless, only treatment i.p. with the peptide B(2)receptor antagonist, Hoe 140, but not the B(1)receptor antagonist (DALBK), inhibited the pruritogenic response to trypsin. Hoe 140 was also effective against SLIGRL-NH(2)-induced scratching behaviour when injected by i.d. or intrathecal (i.t.) routes. Also, the response to SLIGRL-NH(2) was inhibited by i.t. (but not by i.d.) treatment with DALBK. Conversely, neither Hoe 140 nor DALBK were able to inhibit SLIGRL-NH(2)-induced scratching behaviour when given intracerebroventricularly (i.c.v.).. The present results demonstrated that kinins acting on both B(1) and B(2) receptors played a crucial role in controlling the pruriceptive signalling triggered by PAR-2 activation in mice.

Topics: Animals; Antipruritics; Behavior, Animal; Bradykinin; Bradykinin B1 Receptor Antagonists; Bradykinin B2 Receptor Antagonists; Dioxoles; Disease Models, Animal; Dose-Response Relationship, Drug; Injections, Intradermal; Injections, Intraperitoneal; Injections, Intraventricular; Injections, Spinal; Mice; Mice, Inbred C57BL; Mice, Knockout; Oligopeptides; Pain Threshold; Pruritus; Quinolines; Receptor, Bradykinin B1; Receptor, Bradykinin B2; Receptor, PAR-2; Sulfonamides; Trypsin