Immunohistochemical localization of paraquat in lung and brain.

In order to observe the localization and dynamics of paraquat in lung and brain, immunohistochemical approaches were conducted by using animals. Experimental paraquat-poisoned rats were sacrificed 3 hours, 12 hours, 24 hours, 3 days, 7 days and 10 days after intravenous administration of paraquat (5 mg/kg). In lung tissues, paraquat was localized in histiocytes, walls of blood vessels and bronchiolar epithelial cells from 3 hours to 10 days after the paraquat exposure, and interstitial pulmonary fibrosis was being developed with time. On the other hand, in brain tissues, paraquat was localized only in capillary walls and glial cells but not observed in nerve cells 10 days after the administration of paraquat.