Open AccessPAC1 Receptor-Mediated Relaxation of Longitudinal Muscle of the Mouse Proximal Colon
Author(s) -
Kusuhiro Mukai,
Yuji Satoh,
Akikazu Fujita,
Hitoshi Hashimoto,
Akemichi Baba,
Fumiaki Hata
Publication year - 2002
Publication title -
japanese journal of pharmacology/japanese journal of pharmacology
Language(s) - English
Resource type - Journals
eISSN - 1347-3506
pISSN - 0021-5198
DOI - 10.1254/jjp.90.97
Subject(s) - receptor , chemistry , endocrinology , pituitary adenylate cyclase activating peptide , medicine , mutant , adenylate kinase , proximal colon , vasoactive intestinal peptide , relaxation (psychology) , wild type , biology , neuropeptide , biochemistry , colorectal cancer , cancer , gene
Since pituitary adenylate cyclase-activating polypeptide (PACAP) was shown to partially mediate nonadrenergic, noncholinergic (NANC) relaxation of longitudinal muscle of the proximal colon of ICR mice, we further studied the receptor subtype activated by PACAP by using a mutant mouse whose PAC1 receptors are markedly reduced. In wild-type mice, the PACAP-mediated component of NANC relaxation was 33%, but it was absent in the mutant mice. The potency of exogenous PACAP in inducing relaxation in the mutant mice was one hundredth of that in wild-type mice. VPAC1 and VPAC2 receptors were not suggested to have any role in the relaxation. These results suggest that PACAP mediates NANC relaxation of longitudinal muscle of mouse proximal colon via PAC1 receptors.