| Co-Investigator(Kenkyū-buntansha) |
FUKUI Mitsuru Osaka City University Medical School, Statistics Research associate, 医学部, 助手 (40173322)
WAKITANI Fmiko Osaka City University Medical School, Preventive Medicine and Environmental Heal, 医学部, 助手 (00201872)
TERAMOTO Keiko Osaka City University Medical School, Preventive Medicine and Environmental Heal, 医学部, 講師 (70047356)
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| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1991: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1990: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1989: ¥1,100,000 (Direct Cost: ¥1,100,000)
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| Research Abstract |
1. When a given amount (0.1, 0.175, 0.25 ml) of styrene was administered intraperitoneally, about 10 to 20% of the dose was excreted in exhaled air. At high doses (0.175 and 0.25 ml), initial excretion tended to be delayed when the styrene concentration in exhaled air was over 20 ppm. After the styrene concentration in exhalred air decreased to 20 ppm, styrene was excrered at a given rate (half-time= about 4 hours), according to rate constant of an exponential function.
2. Rats were dosed with 0.1, 0.125, 0, 175 or 0, 25 ml of styrene intraperitoneally and urine was analyzed for three urinary metabolites (phenylglyoxylic acid (PGA), mandelic acid (MA), hippuric acid (HA)). A peak was reached at 7 to 10 hours following administration for PGA and at 8.5 to 10.5 hours for MA. For these two metabolites, peak-reaching time increased as dose level increased. On the other hand, the peak-reaching time of urinary HA was almost 8 hours following administration. These metabolites decreased exponentially, their half-time was about 7 hours for PGA, about 9 hours for MA and about 20 hours for HA. the ratio of PGA, MA and HA in urinary excretion was about 5 : 1 : 3. The percent ratio of all metabolites excreted/dose declined with dose within the range from 60 to 70%. Judging from the shifts in peak-reaching time and the changes in the all metabolites/dose ratio, it can be speculated that saturation is reached when the styrene dose is high.
3. When styrene was administered to rats, unreacted styrene was excreted in exhaled air. The remaining styrene (about 80% of the dose) was metabolized in the liver and then excreted as PGA, MA and HA in urine.
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