| Project/Area Number |
09671591
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Anesthesiology/Resuscitation studies
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| Research Institution | KINKI UNIVERSITY |
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Principal Investigator |
SHIOKAWA Yasuhiro KINKI UNIVERSITY, Medicine, Anesthesiology, Assistant professor, 医学部, 講師 (90235490)
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| Co-Investigator(Kenkyū-buntansha) |
UNO Hiroshi KINKI UNIVERSITY, Medicine, Anesthesiology, Instructor, 医学部・附属病院, 助手 (40268404)
TAKEMURA Mitsuhiro KINKI UNIVERSITY, Medicine, Anesthesiology, Instructor, 医学部・附属病院, 助手 (30278725)
IZUMI Takafumi KINKI UNIVERSITY, Medicine, Anesthesiology, Associate professor, 医学部・附属病院, 助教授 (40223044)
村上 晴也 近畿大学, 医学部・附属病院, 助手 (90288944)
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| Project Period (FY) |
1997 – 1999
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| Project Status |
Completed (Fiscal Year 1999)
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| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1999: ¥200,000 (Direct Cost: ¥200,000)
Fiscal Year 1998: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1997: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | rabbit / constant flow reperfusion model / inhalation anesthetic / calcium channel opener / BAY K 8644 / calcium channle blocker / nifedipine / hypoxic pulmonary vasoconstriction / ハロタン / カルシウムチャンネルアゴニスト / 肺循環 |
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| Research Abstract |
The inhalation anesthetic inhibits the hypoxic pulmonary vasoconstriction(HPV) response and induces hypoxemia undergoing general anesthesia. The inhibitory mechanism of the HPV response is not clear. We, therefore, have examined mechanism of the HPV response and relationship on halothane-induced inhibition of the HPV response with the voltage-dependent calcium channel. <Method> We have investigated in isolated rabbit lungs ventilated and perfused at a constant flow rate in situ. The hypoxic pressor response (HPR) was assessed by monitoring change in mean pulmonary arterial pressure when the inspired oxygen concentration was changed from 21% to 3%. We have investigated in the 6 groups : repeated hypoxic challenges (n=6), BAY K 8644 (calcium channel opener) 0.05 μM(n=6), nifedipine (calcium channel blocker) 10 μM(n=6), halothane (0,0.5,1,2,3 MAC) alone (n=6), halothane with BAY K 8644 pretreatment (n=6) and halothane with nifedipine pretreatment (n=6), <Results and Discussion> The HPR was stable after repeated hypoxic challenges. This model was shown the HPV responses did not change by repeated challenges and time courses. The HPR was increased 40% after BAY K 8644 pretreatment as was decreased 70% after nifedipine pretreatment. The concentration of intracellar calcium ion at vascular smooth muscle is very important factor to occur the HPV response. It is clear there stands the calcium channel to control concentration of intracellar calcium ion. Halothane inhibited HPR in a dose-related manner. The halothane-induced inhibition of the HPV response was inhibited after BAY K 8644 pretreatment. The HPV response with nifedipine pretreatment was inhibited by high-dose halothane. In conclusion, it is clear the calcium channel participate strongly in mechanism of the HPV response and the halothane-induced inhibition of the HPV response. But, it was suggested there was the other mechanism except the calcium channel on halothane-induced inhibition of the HPV response.
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