Immunohistochemical localization and dynamics of paraquat in the stomach and esophagus of rats.

The dynamics of paraquat in the stomach and esophagus of rats were demonstrated using immunohistochemical techniques. The Rats were killed 3h, 12h, 24h, 3 days, 7 days and 10 days after intravenous administration of paraquat. In the stomach, paraquat was localized in the epithelial cells between 24 h and 10 days after injection, whereas in the esophagus, paraquat was localized in epithelial cells and the lamina propria mucosa between 12h and 10 days after administration. Although these findings were similar to those observed in the intestine of rats, no clear changes in the distribution of paraquat with time were observed, suggesting that the stomach and esophagus are important reservoirs for the redistribution of paraquat.