BHCおよびPCBの生体内動態に関する実験的研究
1978 年 32 巻 6 号 p. 736-746
詳細
1978 年 32 巻 6 号 p. 736-746
β-BHC and PCB are chemically stable compounds, and they are not metabolized very much in vivo. However, there are very few reports about the transfer rates to the next generation.
This paper describes the results of experiments on the accumulation, the decrease and the transfer to the next generation in carps, rats and mice.
The following results were obtained.
1. Under the condition that carps were bred in the water that contained BHC, the amount of BHC in carps was increased in proportion to period of breeding up to 5-6 weeks. However, after 6 weeks, unique phenomena were observed that BHC in carps decreased. As to the decrease, α, γ-BHC decreased within 1 week, to the level of 1.0-1.5μg/g, and independent of quantity and accumulation period. On the contrary, the rate of decrease of β-BHC depended on quantity and period. Then, it was estimated that the maximum concentration of β-BHC in carps was about 500 times the concentration of breeding, and that of PCB in carps was about 6, 000 times. In the decrease, the biological half time of PCB in carps was about 5 weeks.
2. In mice, the gastrointestinal absorption rates of β-BHC ranged from 80% to 90%, then, most of β-BHC absorbed was accumulated in the tissue of fat. However, γ-BHC had little tendency to be accumulated. The decrease of β-BHC continued through two stages, and the first stage continued within ten days. The biological half time of β-BHC was about 2.5 days for the first stage decrease, and about 18 days for the second stage.
3. By the administration of β-BHC in rats in pregnancy, the transfer rates to fetus through the placenta were measured, and the rate was estimated to be about 40%. On PCB to mice, the rates were 2.6% (by KC-400) and 1.3% (by KC-500), respectively.
4. By the administration of β-BHC in rats after delivery, the transfer rates for offsprings through lactation were measured, and the rate was estimated to be 64%. On PCB (by KC-400), the rate for mice was 10%.
5. β-BHC stored in the fat tissue of rats was transported to offsprings through lactation, and transfer rate was estimated 85.1%. On PCB (KC-400 and KC-500) for mice, the rates were estimated to be 64.3% and 75%, respectively.
