Itch-scratch responses induced by lysophosphatidic acid in mice.
The present investigation was conducted in order to determine whether lysophosphatidic acid (LPA) induces itch-scratch responses (ISRs) in mice. Intradermal administration of LPA induces ISRs; furthermore, the time course for LPA-induced ISRs was similar to that for histamine-induced responses. Comparative study of the pruritogenic activity revealed that histamine possessed a potent effect characterized by a dose-response relationship; however, prostaglandin D2 failed to induce this response. Pretreatment with ketotifen, a histamine H1 receptor antagonist, and capsaicin inhibited LPA-induced ISRs. Additionally, LPA-induced ISRs were abolished by Y-27632, an inhibitor of Rho-associated protein kinase (ROCK). These findings suggest that LPA-induced ISRs are attributable to histamine- and substance-P-mediated pathways. Moreover, the Rho/ROCK-mediated pathway may be involved.
Department of Pharmacology, School of Pharmaceutical Sciences, Showa University, Tokyo, Japan.
Terumasa
T
Hashimoto
Hisayuki
H
Ohata
Kazutaka
K
Momose
D000577:Amides / Q000627:therapeutic use; D000818:Animals; D000982:Antipruritics / Q000627:therapeutic use*; D002211:Capsaicin / Q000627:therapeutic use; D007271:Injections, Intradermal; D047908:Intracellular Signaling Peptides and Proteins; D007665:Ketotifen / Q000627:therapeutic use; D008246:Lysophospholipids / Q000008:administration & dosage / Q000037:antagonists & inhibitors / Q000633:toxicity*; D051379:Mice; D008813:Mice, Inbred ICR; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors*; D011537:Pruritus / Q000139:chemically induced* / Q000517:prevention & control; D011725:Pyridines / Q000627:therapeutic use; D051381:Rats; D054460:rho-Associated Kinases
D000577:Amides; D000982:Antipruritics; D047908:Intracellular Signaling Peptides and Proteins; D008246:Lysophospholipids; D011725:Pyridines; C108830:Y 27632; D017346:Protein Serine-Threonine Kinases; D054460:rho-Associated Kinases; C032881:lysophosphatidic acid; D002211:Capsaicin; D007665:Ketotifen