Protease-activated receptor (PAR)-2-related peptides induce PAR-2-independent tear secretion

PAR-2, upon activation, triggers salivary and pancreatic exocrine secretion. The present study examined and characterized effects of PAR-2-related peptides on tear secretion in rats. A PAR-2-activating peptide, SLIGRL-NH2 (SL), evoked tear secretion, while a reversed peptide, LRGILS-NH2, had no effe...

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Bibliographic Details
Published in:Journal of Pharmacological Sciences 2004, Vol.94 (suppl.2), p.139-139
Main Authors: Hiroyuki Nishikawa, Kenzo Kawai, Makoto Tanaka, Hiroya Ohtani, Shuichi Tanaka, Hiromasa Araki, Atsufumi Kawabata
Format: Article
Language:Japanese
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Summary:PAR-2, upon activation, triggers salivary and pancreatic exocrine secretion. The present study examined and characterized effects of PAR-2-related peptides on tear secretion in rats. A PAR-2-activating peptide, SLIGRL-NH2 (SL), evoked tear secretion, while a reversed peptide, LRGILS-NH2, had no effect. In contrast, another PAR-2-inacitve peptide, LSIGRL-NH2 (LS), caused tear secretion. We then performed in vivo desensitization experiments. After the first dose of SL, but not LS, the second dose of SL produced no response. The first dose of LS blocked the tear secretion caused by the second dose of LS, while the first dose of SL partially inhibited the effect of the second LS. Atropine abolished the tear secretion caused by LS, but only partially blocked the effect of SL. Our findings suggest that LS triggers PAR-2-independent tear secretion in rats by stimulating the parasympathetic nervous system, and that the SL-evoked secretion might involve the PAR-2 pathway and also PAR-2-independent, atropine-sensitive mechanisms.
ISSN:1347-8613