1987 Fiscal Year Final Research Report Summary
Late asthmatic response to Ascaris antigen challenge in dogs treated with metyrapone.
| Project/Area Number |
61570361
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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 |
Respiratory organ internal medicine
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| Research Institution | TOHOKU UNIVERSITY |
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Principal Investigator |
SASAKI Hidetaka Dept. of Geriatrics, Tohoku Univ. School of Medicine, 医学部付属病院, 教授 (20004731)
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| Co-Investigator(Kenkyū-buntansha) |
OKAYAMA Hiroshi Ist Dept. of Internal Medicine, Tohoku Univ. School of Medicine, 医学部, 助手 (10160730)
SHIMURA Sanae Ist Dept. of Internal Medicine, Tohoku Univ. School of Medicine, 医学部付属病院, 助手 (20154312)
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| Project Period (FY) |
1986 – 1987
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| Keywords | Ascari antigen / metyrapone / late asthmatic response / 好中球 |
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| Research Abstract |
We developed an experimental dog preparation that shows a biphasic bronchoconstriction after allergen exposure. After anesthetization, the dogs were intubated with endotracheal tubes and manually ventilated. Respiratory resistance(Rrs)Was measured by the forced oscillation method at 3 Hz.Ascaris suum,diluted from 10^<-5> to 10^<-2> of the extract, was inhaled during tidal breathing for 5 min. One hour before antigen challenge, 10 dogs received 70 mg/kgof metyrapone (cortisolsynthesis inhibitor), and 2 h after antigen challenge 35m g/kg of metyrapone were injected intravenously. In another 10 dogs, metyrapone was not administered. After the maximal increase in Rrs had been assessed(immediate asthmatic response), Rrs increased again 4 to 6 h after antigen challenge in 8 of the 10 dogs treated with metyrapone(late asthmatic response,443(+-)282% mean (+-)SD of initial Rrs), which was significantly higher than Rrs 6 h after antigen challenge (124【plus-minus】41%) in dogs without metyrapone(p<0.01). In another 5 dogs, ragweed challenge with metyrapone caused nochange in Rrs. Bronchoalveolar lavage at the time of the late response revealed a significant correlation between late asthmatic response and neutrophil accumulation(p<0.01) in all dogs. We conclude that cortisol depletion augments the occurrence of the late response. The present dog model may be a useful tool for study of the late response in bronchial asthma.
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Research Products
(4 results)
