A STUDY OF ACUTE TOLERANCE TO AN ANTICONVULSANT EFFECT OF NITROUS OXIDE
| Project/Area Number |
61570737
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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 | KYOTO UNIVERSITY |
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Principal Investigator |
SHINGU KOH KYOTO UNIVERSITY, 医学部, 助教授 (90093252)
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| Project Period (FY) |
1986 – 1987
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| Project Status |
Completed (Fiscal Year 1987)
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| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1987: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1986: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Keywords | Anesthetics / Nitrous oxide / Acute tolerance / Brain electric activity / Analgesic effect / Anticonvulsant effect |
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| Research Abstract |
We firstly documented the acute development of tolerance to the CNS actions of nitrous oxide in cats: the CNS actions of nitrous oxide attenuated by a prolonged exposure. However, we found that the nituous oxide analgesia was not tolerated for 120 min administration in rats. The purpose of the present study was clarification the time course of the development of acute tolerance to the anticonvulsant effect of nitrous oxide in amygdaloid kindling cats.
Adult cats were used. The electrodes were placed in the amygdala, hypocumpus, midbrain reticular formation under pentobarbital-anesthesia. After 1 week of recovery, the animal was stimulated at the amygdala once a day, and the formation of amygdaloid kindling was completed after 3 continuous generalized convulsion was induced by electrical stimulation. The animal was placed in a plastic box. Electroencephalograph and the electrical activity in the midbrain reticular formation were recorded. The cat was electrically stimulated during nitrous oxide inhalation 30min, 1, 2, 5, and 24 hrs. The severities of convulsion was compared and the anticonvulsant effect of nitrous oxide was evaluated. The control convulsion was induced in room air environment.
The nitrous oxide effects on EEG and behavior were observed during 5hr inspiration. Electroencephalogram showed rhythmic slow waves and cats were lying. These effects of nitrous oxide attenuated after 5hr. The anticonvulsant effect of nitrous oxide against to the amygdaloid kindling was maximal until 30min or 1hr, and then the potency of nitrous oxide was attenuated.
This study indicate that nitrous oxide has an anticonvulsant effect, and that the time courses of development of tolerance were different among effects of nitrous oxide observed. These differences would be due to any differences involving neuronal network and/or neurochemical transmitters.
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Report
(2 results)
Research Products
(4 results)
