{
  "abstract": "Platelet-activating factor (PAF) is known to induce smooth muscle contraction; however, its mechanisms in urinary bladder smooth muscle (UBSM) remain unclear. We investigated the involvement of Orai1 in PAF-induced contraction in guinea pig UBSM. PAF (10−6 M)-induced contraction was markedly inhibited by the Orai1 inhibitor Synta66 (10−5 M) and the L-type voltage-dependent Ca2+ channel (VDCC) inhibitor verapamil (10−5 M). Similarly, under Ca2+-free conditions with store depletion induced by cyclopiazonic acid (3 × 10−5 M), Ca2+-induced contraction was suppressed by Synta66 and verapamil. In contrast, Synta66 only partially inhibited contractions induced by acetylcholine (10−5 M) and α,β-methylene ATP (3 × 10−6 M), and it had no effect on high-potassium chloride (80 mM)-induced contraction. Inhibition of Na+/Ca2+ exchanger 1 (NCX1), transient receptor potential canonical (TRPC) 1/4/5 channels, or anoctamin 1 (ANO1) did not significantly affect PAF-induced contraction. These findings suggest that Orai1 contributes to PAF-induced contraction in association with VDCC-dependent mechanisms, whereas NCX1, TRPC1/4/5 channels, and ANO1 play limited roles under these conditions.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": null,
  "author_total": 7,
  "authors": [
    {
      "name": "Keisuke Obara"
    },
    {
      "name": "Daiki Kato"
    },
    {
      "name": "Marina Yuguchi"
    },
    {
      "name": "Momoko Tanaka"
    },
    {
      "name": "Kento Yoshioka"
    },
    {
      "name": "Noritaka Nakamichi"
    },
    {
      "name": "Yoshio Tanaka"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/4d5hk61f8nm62.bib",
  "cited_by": 0,
  "doi": "10.1248/bpb.b26-00187",
  "fulltext_url": "https://www.jstage.jst.go.jp/article/bpb/49/8/49_b26-00187/_article",
  "id": "4d5hk61f8nm62",
  "issns": [
    "1347-5215",
    "0918-6158"
  ],
  "landing_url": "https://www.jstage.jst.go.jp/article/bpb/49/8/49_b26-00187/_article",
  "language": null,
  "licence": "CC-BY-NC",
  "licence_label": "CC BY-NC",
  "licence_source": "journal",
  "licence_url": "https://creativecommons.org/licenses/by-nc/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "jstage-journal",
      "medicine/pharmacology-toxicology"
    ],
    [
      "openalex",
      "2809|Ion Channels and Receptors"
    ]
  ],
  "openalex": "W7204080125",
  "pdf_url": "https://www.jstage.jst.go.jp/article/bpb/49/8/49_b26-00187/_pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-08-25",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/4d5hk61f8nm62.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:32Z",
      "native_id": "10.1248/bpb.b26-00187",
      "source": "jstage",
      "url": "https://www.jstage.jst.go.jp/article/bpb/49/8/49_b26-00187/_article"
    }
  ],
  "subjects": [
    {
      "field": "biology",
      "origin": "openalex:2809|Ion Channels and Receptors",
      "subfield": "neuroscience"
    }
  ],
  "title": "Orai1 Contributes to Platelet-Activating Factor (PAF)-Induced Contraction in Association with Voltage-Dependent Ca²⁺ Channel-Mediated Mechanisms in Guinea Pig Urinary Bladder Smooth Muscle",
  "title_text": "Orai1 Contributes to Platelet-Activating Factor (PAF)-Induced Contraction in Association with Voltage-Dependent Ca²⁺ Channel-Mediated Mechanisms in Guinea Pig Urinary Bladder Smooth Muscle",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:17:32Z",
  "url": "https://research.draconitic.com/paper/4d5hk61f8nm62",
  "venue": "Biological and Pharmaceutical Bulletin",
  "versions": []
}