Effects of volatile anesthetics on contraction and intracellular Ca^<2+> in tracheal smooth muscle
Project/Area Number |
03670955
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Research Category |
Grant-in-Aid for General Scientific Research (C)
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Allocation Type | Single-year Grants |
Research Field |
外科・放射線系歯学
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Research Institution | Iwate Medical University |
Principal Investigator |
KUJI Akiyoshi Iwate Medical University Department of Dentistry Lecturer, 歯学部, 講師 (50225140)
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Co-Investigator(Kenkyū-buntansha) |
SATO Masahito Iwate Medical University Department of Dentistry assistant, 歯学部, 助手 (60215845)
JOH Shigeharu Iwate Medical University Department of Dentistry Professor, 歯学部, 教授 (20154411)
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Project Period (FY) |
1991 – 1992
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Project Status |
Completed (Fiscal Year 1993)
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Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1992: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1991: ¥1,300,000 (Direct Cost: ¥1,300,000)
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Keywords | cytosolic calcium / contraction / bronchial smooth muscle / halothane / histamine / oxygen / fura-2 / pulmonary arterial smooth muscle / カフェイン / 細胞内カルシウム濃度 / 平滑筋 / 気管 / 螢光色素 |
Research Abstract |
In order to investigate the mechanisms of preserving the normal ventiration/perfusion ratio, the cytosolic Ca^<2+>level ([Ca^<2+>]_<cyt>) by means of a fluorecence dye, fura-2 and contraction were measured simultaneusly in the isolated porcine bronchial and pulmonary arterial smooth muscle. Effects of halothane on bronchial smooth muscle Bronchial smooth muscles were stimulated with high extracellular K^+. Halothane (1.0-4.0%) caused dose-dependent depressions of the [Ca^<2+>]_<cyt> transient depressing contraction. Therefore, one of the mechanisms depressing contraction is the inhibition of increase in [Ca^<2+>]_<cyt.> Effects of histamine on bronchial smooth muscle The effects of histamine, a facter of asthma, and caffeine, a special remedy of asthma, is investigated. At the contraction by histamine, [Ca^<2+>]_<cyt> showed biphasic increase, transient large one and following tonic one. Without extracellular calcium ion, the contraction was decreased and the increase in [Ca^<2+>]_<cyt> was transient by histamine. Therefore, the contraction of tracheal smooth muscle by histamine heve connection with both extracellular and intracellular calcium. Effects of oxygen and carbon dioxide on pulmonary arterial smooth muscle High concentration oxygen reinfoce the increase in both contraction and [Ca^<2+>]_<cyt> of pulmonary arterial smooth muscle. On the other hand, high concentration carbon dioxide inhibit the increase in both contraction and [Ca^<2+>]_<cyt> of pulmonary arterial smooth muscle. Therefore, it is seggested that the effect of high concentration oxygen and carbon dioxide on pulmonary arterial smooth muscle contraction is due to the change of [Ca^<2+>]_<cyt.>
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Report
(3 results)
Research Products
(1 results)