| Project/Area Number |
60570733
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
麻酔学
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| Research Institution | Kinki university |
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Principal Investigator |
ISHIBE Yuichi Kinki University, Scool of Medicine lecturer, 医学部, 講師 (40122014)
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| Co-Investigator(Kenkyū-buntansha) |
UMEDA Takashi Kinki University, School of Medicine assistant, 医学部, 助手 (10168750)
NAKAMURA Masato Kinki University, School of Medicine lecturer, 医学部, 病院講師 (40180393)
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| Project Period (FY) |
1985 – 1986
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| Project Status |
Completed (Fiscal Year 1986)
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| Budget Amount *help |
¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 1986: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1985: ¥900,000 (Direct Cost: ¥900,000)
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| Keywords | Hypoxemia / Pulmonary hypertention / Hypoxic pulmonary vasoconstriction / Halothane / Nifedipine / Prostaglandin / アルミトリン |
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| Research Abstract |
Hypoxic pulmonary vasoconstriction (HPV) reduces the severity of arterial hypoxemia by diverting blood flow away from hypoxic lung regions. But HPV also results in pulmonary hypertension and the vasodilator drugs have been tried to reverse the condition. Drugs that inhibit HPV might impair arterial oxygenation by permitting increased venous admixture from hypoxic or atelectatic areas of the lung. The aim of our experiements were: 1)to clarify the effects of the volatile anesthetic, halothane, on HPV, 2)to reveal the effects of the various vasoactive drugs on HPV, 3)to examine whether halothane results in hypoxemia through the inhibition of HPV and 4)to test the effects of various vasoactive agents in the treatment of hypoxic pulumonary hypertention.
<Method> The experiments were performed with the canine separately ventilated left lower love lung models. Effects of the drugs on HPV were evaluated by measuring the changes of the blood flow to left lower lobe.
<Results> 1)The low concentration of halothane did not inhibit the HPV. 2)When halothane was given to left lower lobe in higher concentrations, halothane attenuate the HPV in dose-dependent fashion. 3)Calcium antagonist, nifedipine, inhibited the HPV, and this inhibition was not only the results of the change of systemic circulation but the result of the direct effects of nifedipine on the constrictiry pulumonary vasculature. 5)Prostaglandine I2 attenuated the HPV. 6)Almitrine strengthen the HPV.
In conclusion, inhibition of HPV due to halothane may be a cause of hypoxemia during general anesthesia. Nifedipine and prostaglandine I2 are the effective inhibitors of the HPV, but they may worsen the hypoxemia.
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