Paraquat Exposure Up-regulates Cyclooxygenase-2 in the Lungs, Liver and Kidneys in Rats

Paraquat is a commonly used herbicide in many countries which can lead to systematic poisoning on exposure, in this study, paraquat (pq)-induced changes in the expression of cyclooxygenase-2 (cox-2) along with biochemical and histopathological changes in the lungs, liver and kidneys were studied. twenty four male wistar rats (180-200 g) were exposed either against saline as control group or various doses of pq (3.5, 7 and 10 mg/kg, sc) as test groups for 7 consecutive days. the animals in test groups demonstrated a significant increase of malondialdehyde and no contents, while a remarkable decrease of total thiol molecules was recorded. histopathological studies revealed a severe alveolar edema and hemorrhages in the lungs, congestion and glycogen degeneration in the liver and multifocal interstitial nephritis along with proximal tubular degeneration in the kidneys. pq up-regulated the cox-2 expression at mrna level significantly in the examined organs. this data suggest that the pqinduced oxidative disturbances and pathological damages can be attributed to the upregulation of cox-2 in examined organs.