1988 Fiscal Year Final Research Report Summary
Kinetics of tetrahydrofuran (THF) in humans and animals
| Project/Area Number |
61570263
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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 |
Hygiene
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| Research Institution | Osaka City University Medical School |
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Principal Investigator |
HORIGUCHI Shun'ichi Osaka City University Medical School, Professor, 医学部, 教授 (60046828)
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| Co-Investigator(Kenkyū-buntansha) |
TERAMOTO Keiko Osaka City University Medical School, Lecturer, 医学部, 講師 (70047356)
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| Project Period (FY) |
1986 – 1988
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| Keywords | Organic solvent / Tetrahydrofuran / THF / Human / Rat / Exhaled air / Alveolar air / Blood / Elimination |
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| Research Abstract |
Human subjects were exposed to THF, after their informed consent had been obtained. THF elimination through expiration was examined during short and long term exposure, and THF elimanation in alveolar air and blood was analyzed after long term exposure. Healthy adult volunteers were exposed to THF via breathing. During THF exposure and at appropriate periods after exposure, the expired air, alveolar air and blood were sampled for gas chromatographic analysis of the THF contents. Following THF exposure at several concentrations between 100 and 400 ppm, the percentage of incorprated thf was about 60% with normal breathing, and about 70% with deep breathing. The elimination of THF in alveolar air following 3-hour exposure to THF was expressed by the following formula at exposure levels of 50 ppm and 200 ppm: Y = A・exp(-At). The half life was about 30 minutes; thus, the rate of elimination was similar between these two exposure levels. In subjects exposed to 50 ppm THF for 6 hours, a trace
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amount of THF was detected in the blood up to 3 hours after the end of exposure. In subjects exposed to 200 ppm THF for 3 hours, the blood THF level was higher one hour after the end of exposure than immediately after it. In subjects exposed to THF for 6 hours, the blood THF level varied greatly among individuals, but each subject showed a decrease in the blood THF level 4 hours after the end of exposure.
Animals were exposed to 140-3940 ppm THF once for 4 hours, and THF concentrations in the exhaled air, blood, brain and adipose tissue were measured after the end of THF exposure. The elimination of via exhaled air in rats was approximately expressed by the exponential function, and the biological half life was about 3 hours, at more than 10 ppm of decreased THF concentration in the exhaled air, and about 20 minutes at less than 10 ppm. THF concentration in the living body increased proportionally to the approximate square of exposure concentration, and the initial concentration increased in proportion to the exposure concentration. The elimination of THF from the blood in rats was also approximarely expressed by the exponential function almost the same as in the exhaled air. The eliminations of the THF from the blood, brain and adipose tissue in mice showed the biological half life of abut 70 minutes, respectively. The ratio of distribution of THF in mice was 1 in the blood, 0.1 in the brain and 0.2 in the adipose tissue. Less
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