{"created":"2023-06-19T12:46:18.695334+00:00","id":6229,"links":{},"metadata":{"_buckets":{"deposit":"6807bf4b-a71d-4806-b080-51300ecddc17"},"_deposit":{"created_by":3,"id":"6229","owners":[3],"pid":{"revision_id":0,"type":"depid","value":"6229"},"status":"published"},"_oai":{"id":"oai:tokyo-metro-u.repo.nii.ac.jp:00006229","sets":["656:687:688:1278:1446"]},"author_link":["20522","20521"],"item_2_alternative_title_19":{"attribute_name":"その他のタイトル","attribute_value_mlt":[{"subitem_alternative_title":"Mechanisms of accelerating effect of blebbistatin on relaxation process of skinned tracheal smooth muscle"}]},"item_2_biblio_info_7":{"attribute_name":"書誌情報","attribute_value_mlt":[{"bibliographicIssueDates":{"bibliographicIssueDate":"2017-03-25","bibliographicIssueDateType":"Issued"},"bibliographicPageEnd":"13","bibliographicPageStart":"1","bibliographic_titles":[{}]}]},"item_2_creator_2":{"attribute_name":"著者(ヨミ)","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"ミハシ, サトコ"}],"nameIdentifiers":[{"nameIdentifier":"20522","nameIdentifierScheme":"WEKO"}]}]},"item_2_date_granted_66":{"attribute_name":"学位授与年月日","attribute_value_mlt":[{"subitem_dategranted":"2017-03-25"}]},"item_2_degree_grantor_64":{"attribute_name":"学位授与機関","attribute_value_mlt":[{"subitem_degreegrantor":[{"subitem_degreegrantor_name":"首都大学東京"}]}]},"item_2_degree_name_63":{"attribute_name":"学位名","attribute_value_mlt":[{"subitem_degreename":"修士（健康科学）"}]},"item_2_description_4":{"attribute_name":"抄録","attribute_value_mlt":[{"subitem_description":"[緒言] ミオシンII阻害薬であるblebbiststinは、平滑筋アクトミオシンATPase活性を10μM程度で抑制する。blebbistatinは平滑筋標本においては収縮のCa^<2+>感受性やミオシン軽鎖リン酸化レベルには影響は与えず、アクチン・ミオシン相互作用を直接抑制することにより、その収縮を抑制するといわれている。blebbistatinはミオシンATPase加水分解サイクルに伴うミオシンのアクチンへの結合・解離に影響を及ぼすことが考えられることから、弛緩過程におけるクロスブリッジの解離にも影響を与えることが推察される。そこで本研究では、細胞膜を化学的に破壊して気管平滑筋スキンド標本のCa^<2+>収縮後の弛緩過程とミオシンATPaseサイクルの影響を受けないrigor形成・解離に対するblebbistatinの効果を動力学的に検討した。[方法] モルモット気管平滑筋に100μMのβ-escinで処理をしてスキンド標本を作製し、圧トランスデューサーに取り付けて等尺性張力を測定した。Ca^<2+>による最大収縮の後、EGTAによりCa^<2+>を素早く除去して弛緩させ、同時にblebbistatinを添加し15分間計測した。また、Ca^<2+>収縮後のrigor状態におけるblebbistatinについても同様の方法で検討した。統計処理はt-testを使用しP＜0.05を有意水準とした。[結果] Ca^<2+>収縮後の弛緩過程において、気管平滑筋スキンド標本は30μM程度で弛緩過程を促進し、回帰分析の結果からラッチの解離を速めていた。一方、Ca^<2+>収縮後のrigor状態では相対張力において有意な弛緩はみられなかったが、回帰分析の結果、30μMでrigorの解離の抑制と収縮後一度外れたクロスブリッジがrigorに移行する割合がコントロール群と比較して少ない値を示した。[考察] Blebbistatinは、ATPやアクチンのミオシンへの結合を直接阻害するのではなく、ミオシン頭部構造変化に影響してアクチン・ミオシン結合を弱めることが知られている。ATPの有無によって、Ca^<2+>収縮で発生した収縮張力のCa^<2+>除去後の減衰過程に対するblebbistatinの影響が異なるのは、blebbistatinがミオシン頭部構造変化に与える効果はミオシン頭部へのATPの結合の有無によって変化することを強く示唆する。平滑筋細胞において無酸素状態における力学反応の実態は不明であるが、blebbistatinはその解明に向けて研究において有用なツールになると考えられる。","subitem_description_type":"Abstract"},{"subitem_description":"Blebbistatin, an inhibitor of myosin II , has an inhibitory effect on smooth muscle actomyosin ATPase activity at around 10μM. Blebbistatin is also known to suppress the smooth contraction by direct inhibition of myosin-actin interaction without any effects on Ca^<2+> sensitivity to the force or phosphorylation level of myosin light chain. In the present study, to assess the blebbistatin effects on actin-myosin interaction in detail, we investigated effect of blebbistatin in the relaxation process and the reducing rigor tension after the Ca^<2+>-induced contraction using with skinned tracheal smooth muscle kinetically. A tracheal muscle preparation skinned (cell membrane permeabilized) with 100μM β-escin was attached to a force transducer to measure tension mechanical force. After contractile force induced with 10μM Ca^<2+> reached a steady level, Ca^<2+> was quickly removed in the absence or presence of ATP, resulting in relaxation process or reducing rigor tension respectively, with or without blebbistatin for 15 min. The relaxation process after the Ca^<2+>-removal was accelerated in the presence of 30μM blebbistatin and this effect of blebbistatin seemed to result from acceleration of detach from so called “latch” state. On the other hand, blebbistatin at 301M accelerated detachment of rigor bridge and reduced the forming rigor bridges in the absence of ATP, although the agent did not significantly changes in the tension level during decrease in the rigor tension after Ca^<2+> removal. The difference of the blebbistatin effects on the force between relaxation process and reducing rigor tension seems to be due to distinct effects of the agent on conformational changes of myosin in the absence and presence of ATP, because blebbistatin is known not to directly inhibit ATP binding to myosin, but to actin binding affinity of myosin.","subitem_description_type":"Abstract"}]},"item_2_description_5":{"attribute_name":"内容記述","attribute_value_mlt":[{"subitem_description":"首都大学東京, 2017-03-25, 修士（健康科学）","subitem_description_type":"Other"}]},"item_2_version_type_16":{"attribute_name":"著者版フラグ","attribute_value_mlt":[{"subitem_version_resource":"http://purl.org/coar/version/c_ab4af688f83e57aa","subitem_version_type":"AM"}]},"item_creator":{"attribute_name":"著者","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"三橋, 里子"}],"nameIdentifiers":[{}]}]},"item_files":{"attribute_name":"ファイル情報","attribute_type":"file","attribute_value_mlt":[{"accessrole":"open_date","date":[{"dateType":"Available","dateValue":"2017-09-15"}],"displaytype":"detail","filename":"T01110-001.pdf","filesize":[{"value":"969.6 kB"}],"format":"application/pdf","licensetype":"license_note","mimetype":"application/pdf","url":{"label":"T01110-001.pdf","url":"https://tokyo-metro-u.repo.nii.ac.jp/record/6229/files/T01110-001.pdf"},"version_id":"04eee0da-15b4-454b-ac8e-b2446d507900"}]},"item_keyword":{"attribute_name":"キーワード","attribute_value_mlt":[{"subitem_subject":"気道平滑筋","subitem_subject_scheme":"Other"},{"subitem_subject":"ラッチ","subitem_subject_scheme":"Other"},{"subitem_subject":"ブレビスタチン","subitem_subject_scheme":"Other"},{"subitem_subject":"アクチン・ミオシン相互作用","subitem_subject_scheme":"Other"},{"subitem_subject":"airway smooth muscle","subitem_subject_scheme":"Other"},{"subitem_subject":"latch","subitem_subject_scheme":"Other"},{"subitem_subject":"blebbistatin","subitem_subject_scheme":"Other"},{"subitem_subject":"actin-myosin interaction","subitem_subject_scheme":"Other"}]},"item_language":{"attribute_name":"言語","attribute_value_mlt":[{"subitem_language":"jpn"}]},"item_resource_type":{"attribute_name":"資源タイプ","attribute_value_mlt":[{"resourcetype":"thesis","resourceuri":"http://purl.org/coar/resource_type/c_46ec"}]},"item_title":"Blebbistatinによる気管平滑筋スキンド標本弛緩促進作用のメカニズム","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"Blebbistatinによる気管平滑筋スキンド標本弛緩促進作用のメカニズム"}]},"item_type_id":"2","owner":"3","path":["1446"],"pubdate":{"attribute_name":"公開日","attribute_value":"2017-09-29"},"publish_date":"2017-09-29","publish_status":"0","recid":"6229","relation_version_is_last":true,"title":["Blebbistatinによる気管平滑筋スキンド標本弛緩促進作用のメカニズム"],"weko_creator_id":"3","weko_shared_id":3},"updated":"2023-06-19T16:44:56.157902+00:00"}