Nagao M, Takatori T, Inoue K, Shimizu M, Terazawa K, Akabane H
Department of Legal Medicine, Hokkaido University School of Medicine, Sapporo, Japan.
Toxicology. 1990 Aug;63(2):167-82. doi: 10.1016/0300-483x(90)90040-n.
Immunohistochemical techniques were used to observe the localization of paraquat in the small intestine, liver and kidney, organs that absorb and eliminate chemicals. Paraquat-poisoned rats were killed 3 h, 12 h, 24 h, 3 days, 7 days and 10 days after intravenous administration of paraquat. Three hours after injection, paraquat was localized in hepatocytes and in the kidney in the epithelial cells of the distal tubule. The amount of paraquat in the liver and kidney increased by 24 h after the administration and thereafter decreased with time, suggesting that paraquat is secreted into bile and urine. In the intestine, 3 h after injection, paraquat was localized in the epithelial cells. The same finding was also made in rats with a cannulated bile duct. Therefore, it is likely that paraquat is secreted into the gut lumen from epithelial cells and that paraquat secreted from liver into the duodenum is reabsorbed into the epithelial cells of the intestine.
采用免疫组织化学技术观察百草枯在小肠、肝脏和肾脏（吸收和消除化学物质的器官）中的定位。静脉注射百草枯后3小时、12小时、24小时、3天、7天和10天处死百草枯中毒大鼠。注射后3小时，百草枯定位于肝细胞以及远端肾小管的上皮细胞中。给药后24小时，肝脏和肾脏中的百草枯量增加，此后随时间减少，提示百草枯分泌到胆汁和尿液中。在肠道中，注射后3小时，百草枯定位于上皮细胞中。在胆管插管的大鼠中也得到了相同的结果。因此，百草枯很可能从上皮细胞分泌到肠腔中，并且从肝脏分泌到十二指肠中的百草枯会重新吸收入肠上皮细胞。
