{
  "abstract": "γ-Linolenic acid (GLA) is an n-6 polyunsaturated fatty acid (PUFA) with reported vasoprotective effects. GLA has been shown to inhibit contractions in pig coronary arteries via competitive antagonism at prostanoid TP receptors. α-Linolenic acid (ALA), an n-3 PUFA and a structural isomer of GLA, has been shown to inhibit contractions in pig basilar arteries (PBAs) via prostanoid TP receptor antagonism and activation of K+ channels. However, the actions of GLA in cerebral arteries remain unclear. In this study, we examined the effects of GLA on contractile responses in PBAs. GLA (10−5–10−4 M) concentration-dependently inhibited contractions induced by the TP receptor agonist U46619 (3 × 10−8 M) and prostaglandin F2α (PGF2α; 3 × 10−6 M). GLA (3 × 10−6–3 × 10−5 M) shifted the concentration–response curve for U46619 to the right. Schild analysis yielded a slope of 1.33 (95% confidence interval: 0.70–1.96), which was not significantly different from unity, but GLA also reduced the maximal response to U46619. The apparent pA2 value was 5.43. GLA (10−4 M) also inhibited PGF2α-induced contractions in the presence of the TP receptor antagonist SQ 29,548 (10−6 M); this inhibitory effect was attenuated by Ba2+ (10−3 M) but not by other tested K+ channel inhibitors. GLA also inhibited endothelin-1 (10−8–3 × 10−8 M)-induced contractions, and this effect was attenuated by Ba2+. These findings indicate that GLA, like ALA, suppresses contractile responses in PBAs through dual mechanisms involving TP receptor antagonism and activation of Ba2+-sensitive K+ channels.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": null,
  "author_total": 8,
  "authors": [
    {
      "name": "Kento Yoshioka"
    },
    {
      "name": "Minami Inagaki"
    },
    {
      "name": "Tam Minh Phi"
    },
    {
      "name": "Haruki Kimura"
    },
    {
      "name": "Keigo Osa"
    },
    {
      "name": "Keisuke Obara"
    },
    {
      "name": "Noritaka Nakamichi"
    },
    {
      "name": "Yoshio Tanaka"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/4b4g04124e74y.bib",
  "cited_by": 0,
  "doi": "10.1248/bpb.b26-00185",
  "fulltext_url": "https://www.jstage.jst.go.jp/article/bpb/49/9/49_b26-00185/_article",
  "id": "4b4g04124e74y",
  "issns": [
    "1347-5215",
    "0918-6158"
  ],
  "landing_url": "https://www.jstage.jst.go.jp/article/bpb/49/9/49_b26-00185/_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",
      "1303|Eicosanoids and Hypertension Pharmacology"
    ]
  ],
  "openalex": "W7207722940",
  "pdf_url": "https://www.jstage.jst.go.jp/article/bpb/49/9/49_b26-00185/_pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-04",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/4b4g04124e74y.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:32Z",
      "native_id": "10.1248/bpb.b26-00185",
      "source": "jstage",
      "url": "https://www.jstage.jst.go.jp/article/bpb/49/9/49_b26-00185/_article"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "jstage-journal:medicine/pharmacology-toxicology",
      "subfield": "pharmacology-toxicology"
    }
  ],
  "title": "γ-Linolenic Acid Inhibits Contractile Responses in Pig Basilar Arteries via Prostanoid TP Receptor Antagonism and Ba²⁺-Sensitive K⁺ Channel Activation",
  "title_text": "γ-Linolenic Acid Inhibits Contractile Responses in Pig Basilar Arteries via Prostanoid TP Receptor Antagonism and Ba²⁺-Sensitive K⁺ Channel Activation",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:17:32Z",
  "url": "https://research.draconitic.com/paper/4b4g04124e74y",
  "venue": "Biological and Pharmaceutical Bulletin",
  "versions": []
}